Paraskevi Papaioannidou is a professor of Pharmacology in Medical Faculty of the Aristotle University of Thessaloniki, Greece. She graduated in Chemistry and Medicine at the Aristotle University of Thessaloniki, and she has a Ph.D. in Pharmacology. She had a post-graduate education in the Department of Pharmacology, Μedical Faculty, University of Alberta, Canada, and a post-doctoral education in Gas Chromatography, in Unicam Laboratories, Cambridge, UK. She was a visiting researcher in the 1st Clinic of Obstetrics and Gynecology (Division of Assisted Reproduction, Sant’ Orsola Hospital) in Μedical Faculty of the University of Bologna for one year. She has been an invited lecturer and researcher in the Department of Pharmacology, Clinical Pharmacology and Toxicology, of the Faculty of Μedicine in the University of Novi Sad, and in the Department of Pharmacology and Clinical Pharmacology of the Faculty of Μedicine in the University of Kragujevac.
She has published more than 100 articles in peer review journals on Antimicrobial Chemotherapy, Reproductive Pharmacology, Gender related Pharmacology, Sexual differentiation of the brain, Prostaglandins and Drug Interactions. She has created and is the co-ordinator of two European research networks supported by the Aristotle University: follicle net (website: folliclenet.web.auth.gr) and AntibioSurv (website: antibiosurv.web.auth.gr). She has organized and is the coordinator of medical and interdisciplinary institutional and inter-institutional post-graduate programs.
She has organized and participated in many multicentric European and international research projects. She is the organizer and leader of ASPPOC (a multicentric European project with participation of 40 Surgery and Pharmacology Departments from 12 countries), she has participated in SIG-DUR (an international multicentric study of ΙSPE on cross-national comparison of Drug Utilization, with the participation of 24 countries), and she had a collaboration with ΝΙΗ, Bethesda, USA. One of her PhD students has received the Milton Huppert Graduate Student Award of the Medical Mycological Society of the Americans (May 2007, Toronto, Canada).
Research Experience:
Influence of soy diet on reproduction Ιnvestigation of pharmacodynamic and toxicological effects of medicinal plants extracts grown in the territory of Voivodina AntibioSurv Project on Peri-Operative Chemoprophylaxis Pharmacodynamic interactions of Antimicobial and immunomodulating agents Expression of steroid receptors on the reproductive system and other tisues Controlled Ovarian Stimulation in Assisted Reproduction In vitro fertilization of oocytes and spermatozoa
Teaching activities:
Undergraduate: Pharmacology Clinical Pharmacology Molecular Pharmacology Postgraduate: Antimicrobial Chemotherapy Reproductive Pharmacology Language and Voice Processing
Board memberships:
DOATAP - Hellenic NARIC - Member of the Board GSP - Greek Society of Pharmacology -Member of the Executive Committee Vice-President of "Saint George" - Σύλλογος των απανταχού Κορησωτών (Association of far and wide people from Korisos) European Educational Programmes Department of the Aristotle University of Thessaloniki, Member of the EUREP Committee SAEP - President of the Committee on Pharmacy XEMET 2010 - President 4th European Summer School in Clinical Pharmacology and Therapeutics - Member of the International Advisory Board
Abstract: Aspergillus is damaged by polymorphonuclear neutrophils (PMNs) by means of nonoxidative and oxidative mechanisms, which may be affected by antifungal and antibacterial agents that patients with invasive pulmonary aspergillosis often receive. The pharmacodynamic interactions among deoxycholate amphotericin B (AMB), ciprofloxacin (CIP), and human PMNs against Aspergillus fumigatus growth are unknown. We therefore studied the interactions between 0.032 to 2.0 μg/ml of AMB, 0.1 to 50 μg/ml of CIP at a fixed AMB/CIP ratio of 1:3.125, and PMNs from six donors at an effector-to-target (E:T) ratio of 400:1 against a clinical A. fumigatus isolate using an XTT metabolic assay and the Bliss independence pharmacodynamic-interaction model. CIP exhibited no antifungal activity alone or in combination with PMNs. Synergy was found between AMB and PMNs, with interaction indices (II) of 0.06 to 0.21; the highest interaction of 21% ± 3.6% was observed at 0.22 ± 0.09 μg/ml of AMB. The AMB and CIP (AMB+CIP) combination was synergistic (II = 0.39) at low AMB concentrations and antagonistic (II = 1.39) at high AMB concentrations, with a maximal synergistic interaction of 16% ± 3.7% observed at 0.16 ± 0.08 μg/ml of AMB. The triple combination AMB+CIP+PMNs was synergistic, with interaction indices of 0.05 to 0.20, and a maximal synergistic interaction of 24% ± 4% was observed at 0.20 ± 0.07 μg/ml of AMB. The increased percentage of Bliss synergy of the triple combination AMB+CIP+PMNs (24% ± 4%) was the product of those of the constituent double combinations AMB+PMNs (21% ± 3.6%) and AMB+CIP (16% ± 3.7%). Thus, the antifungal activity of AMB, at clinically relevant concentrations, was enhanced in combination with PMNs and CIP against A. fumigatus growth in a concentration-dependent manner.
Abstract: The aim of this study was to evaluate the pharmacokinetics and efficacy of posaconazole (PSC) in combination with granulocyte colony-stimulating factor (G-CSF) in a neutropaenic murine model of disseminated zygomycosis (mucormycosis) due to Rhizopus microsporus. Male BALB/c mice were rendered neutropaenic with cyclophosphamide (200âmgâkg(-1) , intraperitoneally) administered on days -1 and +5 postinfection. Mice were infected with R. microsporus (5âÃâ10(4) sporesâml(-1) ) intravenously. Mice were treated with PSC (40âmgâkg(-1â) day(-1) by gavage) or G-CSF (300âμgâkg(-1â) day(-1) subcutaneously) or with the combination of PSC and G-CSF. The fungal burden was assessed by culturing the brain, liver, kidneys and lungs. Blood levels of PSC were measured by high performance liquid chromatography. The survival rates were 33%, 27% and 31% for PSC-treated-, G-CSF-treated- and PSCâ+âG-CSF-treated mice, respectively, as compared to 18% for the controls (Pâ=âNS). PSC monotherapy and combination therapy significantly reduced the fungal burden in the kidneys, but not in the rest of the organs. Combination therapy was not superior to PSC monotherapy in terms of either survival or reduction in fungal burden. Serum concentrations of PSC were well-above the MIC of PSC for the particular isolate. PSC monotherapy has a modest efficacy against R. microsporus in reducing fungal burden in neutropaenic mice. Combining G-CSF with PSC does not substantially affect the antifungal activity of PSC.
Abstract: Digit ratios, such as the second to fourth digit ratio (2D:4D), are biometric markers that are influenced by estrogen and testosterone concentrations in utero and are determined genetically by HOX genes (homeodomain-containing homeotic genes). Sex steroids also play a crucial role in the occurrence of myocardial infarction (MI), which is considered to be gender dependent and related to testosterone. Additionally, first-trimester exposure to excess levels of estrogens and progesterone has been linked to cardiovascular anomalies.
Abstract: Purpose A pilot study to assess patients' attitudes towards antimicrobials (ABs) in six European countries (Croatia, Former Yugoslav Republic of Macedonia (FYROM), Greece, Hungary, Slovenia and Serbia), as a step preceding educational intervention on the importance of patients' compliance with instructions on taking ABs and consequences of their inappropriate use. Methods Patients' knowledge, emotions and behaviour regarding ABs were assessed using a structured questionnaire, constructed by a psychologist and intended for general population in six European countries. Questionnaires were filled out by individuals who visited pharmacies and general practitioners. Results A total of 838 questionnaires were filled in. Respondents from Slovenia showed the best knowledge about ABs, followed by Croatians. The highest willingness for self-medication reported respondents from FYROM. The most positive emotions about ABs were expressed by respondents in Greece and Hungary, and the most negative in Slovenia. All components of attitudes towards antibiotics were influenced by country and level of education. Conclusions Behaviour regarding ABs complied with emotions and knowledge in all countries. The results of this study may lay a basis for conducting national public campaigns, as a step forward in education of patients on rational AB use. Copyright (C) 2009 John Wiley & Sons, Ltd.
Abstract: Patients suffering from invasive mycoses often receive concomitant antifungal therapy and antibacterial agents. Ciprofloxacin, a carboxyfluoroquinolone, was previously observed to demonstrate the pharmacodynamic interactions with antifungal agents by altering their growth inhibitory activity against Candida albicans and Aspergillus fumigatus. However, little is known about the interaction between other extended-spectrum fluoroquinolones, such as levofloxacin and moxifloxacin, and antifungal agents against C. albicans and A. fumigatus. Using a microdilution chequerboard technique, we employed isobolographic analysis adapted to incorporate a non-active agent in order to analyse the potential in vitro interaction between ciprofloxacin, levofloxacin or moxifloxacin and the following representative antifungal agents: amphotericin B, fluconazole or voriconazole and caspofungin. Synergistic interactions [interaction indices (Iis) 0.69-0.83, P < 0.05] were observed between amphotericin B (0.07-0.31 mg/L) and either ciprofloxacin (0.19-7.65 mg/L) or levofloxacin (0.41-32.88 mg/L) against C. albicans and A. fumigatus. Synergy (Iis 0.56-0.87, P < 0.05) also was found between voriconazole (0.09-0.14 mg/L) and ciprofloxacin (0.22-11.41 mg/L) as well as between caspofungin (8.94-22.07 mg/L) and levofloxacin (0.14-5.17 mg/L) against A. fumigatus. Some antagonistic (Iis 1.16-1.29, P < 0.05) interactions were observed between fluoroquinolones and fluconazole against C. albicans. In general, ciprofloxacin enhanced the activity of antifungal agents more than moxifloxacin and levofloxacin against both C. albicans and A. fumigatus. The knowledge of the pharmacodynamic interactions between fluoroquinolones and antifungal agents may guide selection and potentially improve the outcome of immunosuppressed patients with concurrent bacterial and fungal infections.
Abstract: Selective and non-selective cyclo-oxygenase (COX) inhibitors impair bone healing by inhibiting prostaglandin synthesis. The purpose of this study was to evaluate the long-term effect of parecoxib, a selective COX-2 inhibitor, on bone healing in rats, when it is applied in a pattern similar to clinical treatment patterns, that is, in a high dose and for a short period after bone fracture. Closed non-displaced mid-diaphyseal fractures in the middle of the left femoral shaft were generated in each animal. In the study group, parecoxib sodium (1.06 mg/kg) was administered intra-peritoneally every day for 7 days. In the control group, normal saline was administered intra-peritoneally every day for 7 days. In both groups fracture healing (bone union and callus formation) was evaluated with X-rays 28 and 42 days after surgery. Bone healing was lower in the study group (60 vs. 80% in the control group 28 days after fracture and 80 vs. 90% 42 days after fracture) but this difference was not statistically significant (P > 0.05). Parecoxib does not have a significant long-term effect on bone healing in rats, when it is administered in a high dose and for a short period after bone fracture.
Abstract: Sometimes resistance of Pseudomonas aeruginosa (Ps. aeruginosa) is developed during antibiotic treatment, in spite of the initial susceptibility in vitro. The aim of this study was to use an in vitro model for the study of the development of resistant strains of Ps. aeruginosa after a short exposure to ceftazidime, and to study the hydrolysing capacity of beta-lactamases produced by the resistant strains.
Abstract: Patients suffering from invasive mycoses often receive concomitant antifungal therapy and antibacterial agents. Ciprofloxacin, a carboxyfluoroquinolone, was previously observed to demonstrate the pharmacodynamic interactions with antifungal agents by altering their growth inhibitory activity against Candida albicans and Aspergillus fumigatus. However, little is known about the interaction between other extended-spectrum fluoroquinolones, such as levofloxacin and moxifloxacin, and antifungal agents against C. albicans and A. fumigatus.
Abstract: Selective and non-selective cyclo-oxygenase (COX) inhibitors impair bone healing by inhibiting prostaglandin synthesis. The purpose of this study was to evaluate the long-term effect of parecoxib, a selective COX-2 inhibitor, on bone healing in rats, when it is applied in a pattern similar to clinical treatment patterns, that is, in a high dose and for a short period after bone fracture.
Abstract: A pilot study to assess patients' attitudes towards antimicrobials (ABs) in six European countries (Croatia, Former Yugoslav Republic of Macedonia (FYROM), Greece, Hungary, Slovenia and Serbia), as a step preceding educational intervention on the importance of patients' compliance with instructions on taking ABs and consequences of their inappropriate use.
Abstract: The 2(nd) to 4(th) digit ratio (2D:4D) is a sexually dimorphic biometric marker, related to prenatal estrogen and testosterone levels in utero, and determined genetically by the HOX genes. 2D:4D presents a population variation, which seems to be dependent on geographical position or ethnicity, and may reflect differences in prenatal steroid hormone levels among different ethnic groups. In view of its clinical importance, this study investigates the 2D:4D ratio, as well as other digit ratios, in Greek population. A sample of 60 Greek men and 60 Greek women (age range 19-25 years) was selected by random procedures. Fingers' length was measured twice, using an electronic vernier calliper (precision 0.01 mm). Men had lower 2D:4D ratio (0.974 +/- 0.035 for the right hand and 0.973 +/- 0.044 for the left hand.) than women (1.002 +/- 0.04 for the right hand and 1.001 +/- 0.045 for the left hand). This difference in 2D:4D ratio between sexes was statistically significant (p<0.0001 for the right hand and p<0.001 for the left hand). The other digit ratios were also lower in men than women for both hands; this difference was statistically significant for all digit ratios of the right hand and for the 2(nd) to 3(rd) (2D:3D) and 2(nd) to 5(th) (2D:5D) digit ratios of the left hand. The digit ratios are lateralized and sexually dimorphic in Greek population. The sexual dimorphism of all digit ratios (except 2D:3D) is stronger in right than left hand.
Abstract: The 2nd to 4th digit ratio (2D:4D) is a sexually dimorphic biometric marker, related to prenatal estrogen and testosterone levels in utero, and determined genetically by the HOX genes. 2D:4D presents a population variation, which seems to be dependent on geographical position or ethnicity, and may reflect differences in prenatal steroid hormone levels among different ethnic groups. In view of its clinical importance, this study investigates the 2D:4D ratio, as well as other digit ratios, in Greek population. A sample of 60 Greek men and 60 Greek women (age range 19-25 years) was selected by random procedures. Fingers' length was measured twice, using an electronic vernier calliper (precision 0.01 mm). Men had lower 2D:4D ratio (0.974 +/- 0.035 for the right hand and 0.973 +/- 0.044 for the left hand) than women (1.002 +/- 0.04 for the right hand and 1.001 +/- 0.045 for the left hand). This difference in 2D:4D ratio between sexes was statistically significant (p < 0.0001 for the right hand and p < 0.001 for the left hand). The other digit ratios were also lower in men than women for both hands; this difference was statistically significant for all digit ratios of the right hand and for the 2nd to 3rd (2D:3D) and 2nd to 5th (2D:5D) digit ratios of the left hand. The digit ratios are lateralized and sexually dimorphic in Greek population. The sexual dimorphism of all digit ratios (except 2D:3D) is stronger in right than left hand.
Abstract: Patients suffering from invasive mycoses often receive concomitant antifungal therapy and antibacterial agents. Assessment of pharmacodynamic interactions between antifungal and antibacterial agents is complicated by the absence of a common antifungal end point for both agents. Ciprofloxacin has no intrinsic antifungal activity but may interact with antifungal agents, since it inhibits DNA gyrase (topoisomerase II), which is abundant in fungi. We therefore employed isobolographic analysis adapted to incorporate a nonactive agent in order to analyze the potential in vitro interaction between the fluoroquinolone ciprofloxacin and several representative antifungal agents against Candida albicans and Aspergillus fumigatus strains by using a microdilution checkerboard technique. In agreement with earlier in vitro studies, conventional fractional inhibitory concentration index analysis was unable to detect interactions between ciprofloxacin and antifungal agents. However, isobolographic analysis revealed significant pharmacodynamic interactions between antifungal agents and ciprofloxacin against C. albicans and A. fumigatus strains. Amphotericin B demonstrated concentration-dependent interactions for both species, with synergy (interaction indices, 0.14 to 0.81) observed at ciprofloxacin concentrations of <10.64 microg/ml. Synergy (interaction indices, 0.10 to 0.86) was also found for voriconazole and caspofungin against A. fumigatus. Isobolographic analysis may help to elucidate the pharmacodynamic interactions between antifungal and non-antifungal agents and to develop better management strategies against invasive candidiasis and aspergillosis.
Abstract: Patients suffering from invasive mycoses often receive concomitant antifungal therapy and antibacterial agents. Assessment of pharmacodynamic interactions between antifungal and antibacterial agents is complicated by the absence of a common antifungal end point for both agents. Ciprofloxacin has no intrinsic antifungal activity but may interact with antifungal agents, since it inhibits DNA gyrase (topoisomerase II), which is abundant in fungi. We therefore employed isobolographic analysis adapted to incorporate a nonactive agent in order to analyze the potential in vitro interaction between the fluoroquinolone ciprofloxacin and several representative antifungal agents against Candida albicans and Aspergillus fumigatus strains by using a microdilution checkerboard technique. In agreement with earlier in vitro studies, conventional fractional inhibitory concentration index analysis was unable to detect interactions between ciprofloxacin and antifungal agents. However, isobolographic analysis revealed significant pharmacodynamic interactions between antifungal agents and ciprofloxacin against C. albicans and A. fumigatus strains. Amphotericin B demonstrated concentration-dependent interactions for both species, with synergy (interaction indices, 0.14 to 0.81) observed at ciprofloxacin concentrations of <10.64 mu g/ml. Synergy (interaction indices, 0.10 to 0.86) was also found for voriconazole and caspofungin against A. fumigatus. Isobolographic analysis may help to elucidate the pharmacodynamic interactions between antifungal and non-antifungal agents and to develop better management strategies against invasive candidiasis and aspergillosis.
Abstract: The second to fourth digit ratio (2D:4D) is a sexually dimorphic biometric marker, determined genetically by the HOX genes group and dependent on prenatal estrogen levels in utero. 2D:4D presents a population variation, which seems to be dependent on geographical position. The aim of this study was to investigate the 2D:4D ratio in Greek population. The 2D:4D ratio was measured in a sample of 50 Greek men and 50 Greek women (age range 19 - 25 years). 2D:4D presented a statistically significant difference between sexes for both hands (p<0.001 and p<0.01 for right and left hand). Men have significantly lower 2D:4D (0.971 +/- 0.034 for the right hand and 0.969 +/- 0.045 for the left) than women (1.0 +/- 0.041 for the right hand and 0.996 +/- 0.044 for the left). This finding is in agreement with other studies of 2D:4D in other ethnic groups. To our knowledge, this is the first study of 2D:4D in Greek population.
Abstract: The aim of this study was to compare peri-operative Chemoprophylaxis in Neurosurgery Departments in three University Hospitals in Denmark, Croatia and Greece, and to check if the recommended guidelines for Chemoprophylaxis in Neurosurgery are met. The Neurosurgeons in the three countries replied to the same questionnaire, which investigated the conformance to the guidelines. The following issues of quality in Chemoprophylaxis were checked: application of chemoprophylaxis, duration and time of initiation of chemoprophylaxis and the kind of antibiotics used. The quality of chemoprophylaxis was very good in Denmark. In Croatia and Greece discrepancies in the duration of prophylaxis and the kind of antibiotics used was observed, with use of 3(rd) generation cephalosporins - and even 4(th) generation cephalosporins in Croatia. Neurosurgeons in these countries should show better conformance to the guidelines to improve quality of chemoprophylaxis.
Abstract: The aim of this work is to present contemporary theories of cognitive development and methodology of teaching, with special emphasis on practical problems of teaching and learning in pharmacology. Structuralistic theories of cognitive development, like the genetic psychology of Piaget, the social constructivism of Durkheim and the radical constructivism of von Glaserfeld are presented briefly, with special emphasis on their impact on modern methods of teaching, like problem based teaching. Models of the construction of knowledge are also presented, as well as the theoretical basis of communicative methods in teaching and learning. Common problems of "alternative concepts" or "false conception" in Pharmacology are analysed, and practical advice on memory and its organization is also presented.
Abstract: In the present study we investigated histologically and immunohistochemically the changes in the expression of androgen receptors (AR) in the testes of the adult rat, after a 20-day intramuscular administration of 12.5mg of testosterone enanthate (TE). Male Wistar rats five months old were used for the study. The rats were divided in two groups: in the first group 12.5mg of TE were administered intramuscularly every day for 20 days. In the second group, normal saline was administered in the same way. The immunohistochemical technique of biotin-streptavidin was used and androgen receptors were stained using specific monoclonal antibodies. Treatment with TE decreased the number of Leydig cells (LC) and AR in LC but its action in seminiferous tubules (ST) and in the expression of AR in ST was not constant and seemed to be stage-dependent.
Abstract: The contractile effect of benzylpenicillin on isolated rings of human gallbladder was studied using preparations taken from surgical specimens after gallbladderectomy. The gallbladder was cut into two pieces and one ring was cut from each piece; one ring was mounted in a 100 ml organ bath containing Krebs solution and the isotonic changes of the preparation were recorded for each experiment. Benzylpenicillin (1 x 10(4) to 1 x 10(8) IU/l) was shown to exert a dose-dependent contractile effect on isolated human gallbladder rings which was blocked by atropine (1 x 10(-8) M). The benzylpenicillin-induced contractile effect was analogous to contraction observed with acetylcholine (1 x 10(-7) to 1 x 10(-2) M). The effect of benzylpenicillin on isolated human gallbladder may reflect a possible decrease in gallbladder emptying time in vivo, suggesting a beneficial effect of benzylpenicillin in antimicrobial treatment of gallbladder infections.
Abstract: We conducted an open-label pilot study of dextromethorphan (DM) in intractable partial epilepsy with the following objectives: a preliminary evaluation of the drug's safety and efficacy in the epileptic patient and a definition of a concentration range which can be safely achieved in future studies. Sixteen patients with drug-resistant, localization-related epilepsies entered the trial. After an 8-week baseline period, DM was added to the existing antiepileptic drugs at a dose of 40 and 50 mg every 6 h (160 and 200 mg/day). Each treatment period lasted 8 weeks. Seizure control improved after administration of DM, especially in the group of intermediate and slow metabolizers. Two patients, however, experienced increased seizure frequency and withdrew from the study. Adverse effects during DM administration were mild and transient. DM was well tolerated even in patients with high plasma levels of the drug (up to 15020 ng/dl). Our results indicate that DM is safe and effective in the treatment of comedicated patients with intractable partial epilepsies.
Abstract: We conducted an open-label pilot study of dextromethorphan (DM) in intractable partial epilepsy with the following objectives: a preliminary evaluation of the drug's safety and efficacy in the epileptic patient and a definition of a concentration range which can be safely achieved in future studies. Sixteen patients with drug-resistant, localization-related epilepsies entered the trial. After an 8-week baseline period, DM was added to the existing antiepileptic drugs at a dose of 40 and 50 mg every 6 h (160 and 200 mg/day). Each treatment period lasted 8 weeks. Seizure control improved after administration of DM, especially in the group of intermediate and slow metabolizers. Two patients, however, experienced increased seizure frequency and withdrew from rile study. Adverse effects during DM administration were mild and transient. DM,was well tolerated even in patients with high plasma levels of the drug (up to 15020 ng/dl). Our results indicate that DM is safe and effective bl the treatment of comedicated patients with intractable partial epilepsies. (C) 1999 Pious Science. All rights reserved.
Abstract: Aminoglycoside antibiotics inhibit contractility of the isolated guinea pig vas deferens in a dose-related manner. However, total inhibition of the contractility cannot be attained, a phenomenon most probably attributed to the partial inhibition of the function of Ca channels by the antibiotics. The inhibitory potency of aminoglycoside antibiotics was found to be: sisomicin greater than gentamicin greater than netilmicin greater than streptomycin greater than dactimicin greater than amikacin greater than kanamycin greater than kanendomycin greater than dibekacin greater than tobramycin. Ca2+ antagonize the action of aminoglycoside antibiotics on the vas deferens competitively. This observation indicates that the untoward effect of aminoglycoside antibiotics on contractility of the vas deferens can be attributed to their ability to interfere with Ca2+ entry through cell membranes of the tissue, a prerequisite for subsequent contraction. Above a specific threshold (7.5 mM) Ca2+ have a prophylactic effect on vas deferens and prevent the inhibitory action of ICmax doses of the antibiotics. Thus, Ca could be used as a prophylactic medium or as an antidote in restoring contractility of the vas deferens if it is inhibited by aminoglycoside antibiotics.
Abstract: Kinetic analysis of cGMP phosphodiesterase activity in the rat brain indicated that Km values did not differ significantly with sex, age (1 to 270 days old), or brain area (amygdala, cerebellum, cerebral cortex, hypothalamus, thalamus, reticular formation). There was no dimorphism in enzyme activity between normal or artificially mimicked gender, nor was there any significant variation in activity following short or long term alterations of endogenous levels of gonadal hormones in any of the brain regions investigated. Highest activity was observed in cerebral cortex and amygdala. Maturation caused a significant increase in enzyme activity, the adult levels being reached by the 38th to 40th day of life.
Abstract: High affinity binding of [3H]-dopamine was measured in membrane fractions prepared from cerebral cortex, amygdala, hypothalamus, thalamus and reticular formation of female rats aged 1 to 260 days old. [3H]-dopamine bound with approximately 30 x 10(-9) M affinity to neural membrane fractions of female brains of any age. [3H]-dopamine binding increased with age either in a sigmoid fashion, as was the case in the amygdala, hypothalamus and reticular formation, or in a parabolic fashion, as was the case in the cerebral cortex and thalamus, the adult levels being reached on the 30th and 70th day of life respectively.
