The relationship of maternal age, BMI, serum Tenascin-C, and HOMA-IR values with gestational diabetes mellitus.

Objectives: To explore the relationship, if any, of gestational diabetes mellitus with maternal age, body mass index, serum tenascin-C and homeostatic model assessment for insulin resistance, and to see if these could act as predictive markers for gestational diabetes mellitus. METHODS: The case-control study was conducted from February to August 2022 at the outpatient department of gynaecology and obstetrics at the Civil Hospital, Karachi, and comprised pregnant females aged 18-40 years having gestational age 20-34 weeks. After noting down baseline characteristics and anthropometric measurements, the participants were subjected to oral glucose tolerance test on the basis of which they were divided into three groups; pregnant healthy controls in group 1, those with gestational diabetes mellitus on diet control in group 2, and those with gestational diabetes mellitus taking medicines for the condition in group 3. Fasting serum samples were used for further analysis using enzyme-linked immunosorbent assay kits. Data was analysed using SPSS 21. RESULTS: Of the 90 subjects, 30(33.3%) were in group 1 with mean age 26.0±4.9 years, 30(33.3%) were in group 2 with mean age 30.7±5.6 years, and 30(33.3%) were in group 3 with mean age 29.1±5.5 years. Age, gestational age, body mass index and homeostatic model assessment for insulin resistance values were significantly higher in groups 2 and 3 compared to group 1 (p<0.05), while serum Tenascin-C values were not significantly different (p>0.05). CONCLUSIONS: HOMA-IR values and BMI were more reliable in diagnosing GDM before its onset, and should be included in the screening test for GDM in early pregnancy.

1st International Conference on Biomedical Sciences, Dow University of Health Sciences, Karachi Pakistan.

Institute of Biomedical Sciences (IBMS) at Dow University of Health Sciences (DUHS), organised a two day's conference on Biomedical Sciences. IBMS being the part of one of the largest public sector health universities of Pakistan, is now transforming the research trends to be effectively translated at the community level. Currently with a strong PhD faculty line in basic and clinical sciences, DUHS has a significant contribution in research output of the country. The scientific data however represents a small population per scientific study and the generalization of results may not be inferred. It must be extended through translational research for effectiveness. The conference was planned with a theme to bridge the gap between basic and translational research. The two day's conference conducted in second week of March 2023 at Dow International Medical College Ojha Campus DUHS was able to attract more than 300 participants. The scientific sessions encompassed a vast variety of health issues and their proposed solutions including neurosciences, virtual biopsies, metabolomics, medical writings and incorporation of engineering and artificial intelligence to facilitate detection and prognosis of disease. The conference was able to conclude that the multidisciplinary research studies with collaboration of two or more institutes/organizations are the need of time. Young researchers need an effective platform to showcase their research and make collaborations. Moreover, the incorporation of artificial intelligence would enhance patient care within health systems.

Sialuria-Related Intellectual Disability in Children and Adolescent of Pakistan: Tenth Patient Described has a Novel Mutation in the GNE Gene.

BACKGROUND: Sialuria is a rare inborn error of metabolism caused by excessive synthesis of sialic acid due to the mutation in the binding site of the cytidine monophosphate-sialic acid of UDPGlcNAc 2-Epimerase/ManNAc Kinase (GNE/MNK). OBJECTIVE: This is the first study investigating the molecular basis of neuronal disorders exhibiting sialuria in Pakistani children/adolescents. METHODS: The current study genotyped GNE SNPs rs121908621, rs121908622 and rs121908623 by using PCR, RFLP, and DNA sequencing methods. Socioeconomic and clinical histories were also recorded. RESULTS: Our data suggest that clinical symptoms and financial status play a significant role in conferring sialuria related Intellectual Disability (ID). SNP: rs121908623 showed G/A substitution (R263Q) in the GNE gene. CONCLUSION: We have identified one case study in Pakistan, so this makes our research a leap forward towards the identification of the 10th case study worldwide.

Madecassic Acid Reduces Fast Transient Potassium Channels and Promotes Neurite Elongation in Hippocampal CA1 Neurons.

BACKGROUND AND OBJECTIVE: Madecassic Acid (MA) is well known to induce neurite elongation. However, its correlation with the expression of fast transient potassium (AKv) channels during neuronal development has not been well studied. Therefore, the present study was designed to investigate the effects of MA on the modulation of AKv channels during neurite outgrowth. METHODS: Neurite outgrowth was measured with morphometry software, and Kv4 currents were recorded by using the patch clamp technique. RESULTS: The ability of MA to promote neurite outgrowth is dose-dependent and was blocked by using the mitogen/extracellular signal-regulated kinase (MEK) inhibitor U0126. MA reduced the peak current density and surface expression of the AKv channel Kv4.2 with or without the presence of NaN3. The surface expression of Kv4.2 channels was also reduced after MA treatment of growing neurons. Ethylene glycol tetraacetic acid (EGTA) and an N-methyl-D-aspartate (NMDA) receptor blocker, MK801 along with MA prevented the effect of MA on neurite length, indicating that calcium entry through NMDA receptors is necessary for MA-induced neurite outgrowth. CONCLUSION: The data demonstrated that MA increased neurite outgrowth by internalizing AKv channels in neurons. Any alterations in the precise density of ion channels can lead to deleterious consequences on health because it changes the electrical and mechanical function of a neuron or a cell. Modulating ion channel's density is exciting research in order to develop novel drugs for the therapeutic treatment of various diseases of CNS.

Coixol amplifies glucose-stimulated insulin secretion via cAMP mediated signaling pathway.

Recently, we reported the role of coixol (6-methoxy-2(3H)-benzoxazolone), an alkaloid from Scoparia dulcis, in glucose-dependent insulin secretion; however, its insulin secretory mechanism(s) remained unknown. Here, we explored the insulinotropic mechanism(s) of coixol in vitro and in vivo. Mice islets were batch incubated, perifused with coixol in the presence of agonists/antagonists, and insulin secretion was measured by ELISA. Intracellular cAMP levels were measured using enzyme immunoassay. K+- and Ca2+-currents were recorded in MIN6 cells using whole-cell patch-clamp technique. The in vivo glucose tolerance and the insulinogenic index were evaluated in diabetic rats treated with coixol at 25 and 50 mg/kg, respectively. Coixol, unlike sulfonylurea, enhanced insulin secretion in batch incubated and perifused islets at high glucose, with no effect at basal glucose concentrations. Coixol showed no pronounced effect on the inward rectifying K+- and Ca2+-currents in whole-cell patch recordings. Moreover, coixol-induced insulin secretion was further amplified in the depolarized islets. Coixol showed an additive effect with forskolin (10 µM)-induced cAMP level, and in insulin secretion; however, no additive effect was observed with isobutylmethylxanthine (IBMX, 100 µM)-induced cAMP level, nor in insulin secretion. The PKA inhibitor H-89 (50 µM), and Epac2 inhibitor MAY0132 (50 µM) significantly inhibited the coixol-induced insulin secretion (P < 0.01). Furthermore, insulin secretory kinetics revealed that coixol potentiates insulin secretion in both early and late phases of insulin secretion. In diabetic animals, coixol showed significant improvement in glucose tolerance and on fasting blood glucose levels. These data suggest that coixol amplifies glucose-stimulated insulin secretion by cAMP-mediated signaling pathways.

Gallic and vanillic acid suppress inflammation and promote myelination in an in vitro mouse model of neurodegeneration.

Neuroinflammation affects millions of people around the world as a result of injury or stress. Neuroinflammation represents almost all types of neurological diseases such as multiple sclerosis and Alzheimer's disease. Neurodegenerative diseases comprise demyelination and synaptic loss. The inflammatory response is further propagated by the activation of glial cells and modulation of constitutively expressed extracellular matrix proteins. The aim of the present study was to identify the anti-inflammatory effects of purified compounds gallic acid (GA, 1.0 µM) and vanillic acid (VA, 0.2 µM) on the lysolecithin (LPC, 0.003%)-induced model of inflammation. Hippocampal neurons were co-cultured with glial cells, and LPC was added to induce inflammation. Neurite outgrowth was measured by morphometry software. The level of myelination and demyelination was identified by immunostaining and sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blotting techniques using different antibodies. Whole-cell patch clamp recordings were used to observe the sustained repetitive firing pattern. The data showed that GA and VA significantly increased the neurite outgrowth after 48 h in culture. Both compounds significantly reduced the expression of cyclooxygenase-2, NFκB, tenascin-C, chondroitin sulfate proteoglycans and glial fibrillary acidic protein in astrocytes in the LPC-induced model of inflammation. The level of myelin protein in neurites and oligodendrocyte cell bodies was significantly upregulated by GA and VA treatment. The reduction in sustained repetitive firing in the LPC-induced model of inflammation was reversed by both GA and VA treatment. This study supports the hypothesis that VA and GA have anti-inflammatory activities and could be regarded as potential treatments for neurodegenerative disease.

Piperine attenuates the cancerous activity response in Neuro-2a cell line.

Interactions of cancer cells with their microenvironment play a significant role in defining the severity of the disease. In search of novel compounds with anti-inflammatory and anticancerous capabilities, the effects of purified compound piperine were investigated in Neuro-2a cell line. The neuronal lineage of Neuro-2a cell line was confirmed by using antibody against ß-III tubulin protein. The cells were treated with different concentrations of piperine (µM: 10, 50 and 100) for 48 hrs at 37ºC. A dose of 100 µM was selected that induces a 50% inhibition in the cell growth calculated by MTT and morphometery assays. The result shows that in the presence of piperine neurite outgrowth was decreased in a dose dependent manner. The gene expression of TN-C, TNfnD and TnfnC were significantly reduced whereas the expression intensities of TnfnA1, TnfnA2, CSPGs and Laminin were significantly elevated when compared to their respective untreated controls. Similarly proinflammatory marker COX-2 expression was significantly inhibited in the presence of piperine when compared to untreated controls. This is the first time we have illustrated that irrespective of increased expressions of CSPGs, a significant reduction in Tenascin-C and its TNfnD and TNfnC domains are necessary to inhibit the tumor progression. Taken together, the capabilities of piperine to induce an apoptosis by decreasing the neurite outgrowth, proliferation rate and expression of TN-C and COX-2 in Neuro-2a cell line confirmed for its anticancerous and anti-inflammatory potential.

A new indanedione derivative alleviates symptoms of diabetes by modulating RAGE-NF-kappaB pathway in db/db mice.

Accumulating evidence indicates that a number of tissues are damaged due to build-up of abnormal amount of Advanced Glycation End products (AGEs) in several diseases including diabetes. Currently AGE inhibitors are scarce in clinical use indicating a need for development of new anti-AGE agents. The aim of the current study is to identify the new AGE inhibitors and to decipher their mechanism of action for alleviating symptoms of diabetes in mice. Among several derivatives, one of the derivatives of indanedione, IDD-24 demonstrated highest inhibition of AGE formation and AGE mediated reactive oxygen species production in HepG-2 and mature 3T3-L1 adipocytes. In mice treated with IDD-24, reduction in serum AGE formation and expression of Receptor for AGEs (RAGE) was seen in IDD-24 treated db/db mice. In vivo, glycogen synthesis was also increased in muscle tissue. In adipocytes, anti-AGE agent restored AGEs' induced diminished glucose uptake in fat cells. Mice treated with IDD-24 exhibited increased glucose tolerance, increaed serum adiponectin levels and decreased insulin resistance. Deciphering mechanism of IDD-24 in diabetic mice, it was observed that nuclear factor-κB (NF-κB) and serine phosphorylation of Insulin receptor substrate-1 (IRS-1) declined, while diminished activation of c-Jun NH2-terminal kinase (JNK) appears to be partly responsible for restoration of insulin signaling. We conclude that IDD-24 can be a possible treatment target to address symptoms of diabetes.

Neurite outgrowth properties of Calotropis procera: In search for a neuroprotectant.

In view of the well-documented medicinal properties of Calotropis procera (CP), the present study was designed to evaluate the neuroprotective effect of the extract. We have prepared a methanolic extract of Calotropis procera and screen varying concentration of CP (20, 30, 40, 50 and 70µg/ml) for the stimulatory potency on neurite outgrowth. The stimulatory effect of CP on neurite outgrowth was assessed in primary hippocampal neurons. Neurite lengths were measured using optika provison analysis software. Neuritogenesis was further analyzed by immunostaining by using specific neuronal marker ß III-tubulin. The data show that neurite outgrowth from hippocampal neurons were significantly enhanced in the presence of CP (40µg/ml). The most stimulatory neurite outgrowth effects were appeared after 48hrs incubation of neurons with CP (40µg/ml). These data confirm that CP extract could promote invitro hippocampal neurite outgrowth in a dose-dependent manner. Our results indicate that CP can be used as a healthy dietary supplement for the cognitive functions of the brain.

Vitex negundo induces an anticonvulsant effect by inhibiting voltage gated sodium channels in murine Neuro 2A cell line.

Vitex negundo (Vn) extract is famous for the treatment of neurological diseases such as migraine and epilepsy. These neurological diseases have been associated with abnormally increased influx of sodium ions into the neurons. Drugs that inhibit voltage gated sodium channels can be used as potent anti-epileptics. Till now, the effects of Vn on sodium channels have not been investigated. Therefore, we have investigated the effects of methalonic fraction of Vn extract in Murine Neuro 2A cell line. Cells were cultured in a defined medium with or without the Vn extract (100 µg/ml). Sodium currents were recorded using whole-cell patch clamp method. The data show that methanolic extract of Vn inhibited sodium currents in a dose dependent manner (IC50 =161µg/ml). Vn (100 µg/ml) shifted the steady-state inactivation curve to the left or towards the hyper polarization state. However, Vn did not show any effects on outward rectifying potassium currents. Moreover, Vn (100 µg/ml) significantly reduced the sustained repetitive (48±4.8%, P<0.01) firing from neonatal hippocampal neurons at 12 DIV. Hence, our data suggested that inhibition of sodium channels by Vn may exert pharmacological effects in reducing pain and convulsions.

Neuroprotective capabilities of Vitex negundo in primary hippocampal neurons.

Vitex negundu (Vn) is a well-known aromatic shrub commonly used as a traditional folk medicine famous for its potential pharmacological and biological activities. Several chemical compounds are extracted and identified from the different parts of the Vn such as leaves, root, seeds and flowers. Number of researches reported the herb as antimicrobial, anti-androgenic, anti-osteoporotic, and anti-tumour, anti-cancer, anti-inflammatory, anti-oxidant, anti-hyperglycemic and hepatoprotective. The effects of Vn on neurite outgrowth have not been identified till now. Therefore present study was designed to investigate the neurite outgrowth effects of Vn extract in hippocampal neurons. Neurons from P0 mice were isolated and cultured in defined medium containing the different concentrations of Vn (20, 30, 40, 50, 100, 150 and 200 µg/ml) for 48 hrs. The presence of the neurites was confirmed by using ßIII-tubulin antibody which specifically labels only the neurites. Morphometric analysis was done by using Optika Pro-Vision software. The data show that Vn at 30 and 40 µg/ml significantly increased the mean average length of the longest neurite whereas at 150 and 200 µg/ml it significantly decreased the mean average length of the 10 longest neurite in hippocampal neurons. Nevertheless Vn did not show any significant effects on the sum of all the neurite lengths at any concentrations tested. Taken together the result shows that methanolic extract of Vn has potential to produce long neurites at 30 and 40 µg/ml and therefore can be act as a neuroprotective agent in the future drug development.

Cardamom extract induces cell proliferation by increasing potassium currents in NIH3T3 cell line.

Amommum subulatum (Roxb.) or Cardamom extract is known to have anti-inflammatory and neuroprotective effects towards many gastrointestinal related problems. However, uptill now different fractions of cardamom extract on fibroblasts with respect to potassium channel activity have not been investigated. Therefore, present study investigated the effects of different fractions of cardamom extract on potassium channels in non-tumor NIH3T3 cell line. Phytochemical analysis of hydroalcoholic, n-hexane, butane and ethyl acetate fractions of cardamom extracts were purified and isolated by thin layer chromatography (TLC). 3T3 cells were cultured and incubated with hydroalcohol (1-2 µ/ml), n-hexane (1 µ/ml), butane (2 µ/ml) and ethyl acetate (1-2 µ/ml) for 5 hrs at 37°C. Modulation in potassium currents were recorded by whole-cell patch clamp method. The data showed two constituents Cineol (C10H18O) and Terpinyl acetate (C10H17OOCCH3) by TLC method. The present study shows that the constituents in n-hexane, hydro alcohol (1 µ/ml) and ethyl acetate (2 µ/ml) significantly increased (p<0.01) the potassium outward rectifying currents from NIH3T3 cells when compared to untreated controls cells. Whereas, butanol fraction (2 µ/ml) significantly decreased (p<0.01) the inward rectifying currents when compared to controls. Moreover hydroalcoholic and n-hexane fractions have increased the proliferation in 3T3 cell line. On the other hand butanol and ethyl acetate did not induce proliferation in 3T3 cells. Taken together, our data suggested that cardamom extract contains constituents that increased K+ currents, cell migration and proliferation and are involved in wound healing.

Association of Single Nucleotide Polymorphisms in Catechol-O-Methyltransferase and Serine-Threonine Protein Kinase Genes in the Pakistani Schizophrenic Population: A Study with Special Emphasis on Cannabis and Smokeless Tobacco.

Schizophrenia is a neuropsychiatric disorder in which abnormalities in the prefrontal cortex lead to impaired synthesis of dopamine. It is associated with hallucination, psychosis and hearing impairments. Many susceptible genes have been identified in schizophrenia such as catechol-O-methyltransferase (COMT) and serine/threonine kinase (AKT1). Single nucleotide polymorphisms (SNPs) in these genes have not been identified in Pakistan. Therefore, we investigated the allelic and genotypic frequencies in COMT and AKT1 genes in the Pakistani population. Polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) and DNA sequencing were used to identify SNPs in the genes. The present study shows that COMT Val and COMT Met allelic frequencies for the controls were p=0.52, q=0.48 and for the schizophrenic cases they were p=0.34, q=0.66 respectively. The distribution of polymorphism in COMT Val158Met genotype by Hardy-Weinberg equilibrium (HWE) was P=0.61 for controls and P=0.005 for cases. The data reveal that SNP rs1130214 T allele mutation was found neither in patients nor in controls in the 5' untranslated region (UTR). This proves that no association of AKT1 and positive association of COMT with schizophrenia exist in the population of Pakistan. Moreover, a study based on a single family showed COMT Met allele inheritance in schizophrenic offspring. This suggested that COMT allele alteration influences susceptibility to at least some forms of psychosis in the Pakistani population. Interestingly, according to our socio-economical survey, COMT genotype has no association with cannabis but it is strongly associated with tobacco. The Pakistani population with Val158Met SNP showed more susceptibility towards developing schizophrenia. This study highlights the genetic differences between Pakistani and other Caucasian populations.

Drugs targeting SNPrs35753505 of the NRG1 gene may prevent the association of neurological disorder schizophrenia in a Pakistani population.

The Neuregulin 1 (NRG1) gene has been associated with schizophrenia in several populations, and all four types of NRG1 genes are linked with neurotransmitters activities. In this study for the first time we have demonstrated an association between NRG1 mutation and schizophrenia in Pakistani population. We examined the relationship of three genetic variants SNPs: rs3924999, rs2954041 and rs35753505 of NRG1 gene with the onset of disease. Genomic DNA samples were obtained from the blood of 100 patients and 80 matched controls. All three NRG1 SNPs were genotyped by polymerase chain reaction-restriction fragment length polymorphism method and further confirmed by DNA sequencing. The SNPs frequencies were estimated by Hardy-Weinberg equilibrium and Chi-square tests. Our study established a significant association of rs35753505 with schizophrenia but no association with rs3924999 and rs2954041. The frequency of risk allele C was significantly higher (62.5%) in rs35753505 patients when compared to controls (28.13%). Genotype frequency by Hardy-Weinberg equilibrium for SNPrs3924999 in patients was GG 77.4%, GA 21.12% and AA 1.44% and showed no association with the disease. Similarly, no genotype association was observed in rs2954041: GG 92.98%, GT 6.89%, TT 0.13% of NRG1. However, one unexpected G allele, 100% guanine (G) with no adenine (A) was found to be present in SNP rs35753505 in both patients and controls. This is an interesting finding that both cohorts display only allele G peak but no peak for allele A in the electropherogram for this SNP. Our results suggest that SNP rs35753505 of NRG1 plays an important role in conferring susceptibility to the schizophrenia in a Pakistani population.

Comparative screening of glial cell types reveals extracellular matrix that inhibits retinal axon growth in a chondroitinase ABC-resistant fashion.

Glial cells provide an optimal surface for attachment, migration, and growth of CNS neurons. This study was designed to investigate the ability of four glia cell types, retinal Müller Glia (MG), cortical astrocytes (CA), A7, and Oli-neu to support the outgrowth of embryonic day 18 rat retinal explants. Extracellular matrix (ECM) prepared by water lysis of monolayers of A7, CA, and MG cells significantly increased, whereas Oli-neu-derived ECM inhibited fiber growth. Analogous results were obtained with explants on live monolayers. The inhibitory effect of Oli-neu matrix, but not of live cells, could be neutralized with the Rho-kinase inhibitor Y27632. Studies on the message and protein level revealed the expression of a range of ECM glycoproteins and the major chondroitin sulfate proteoglycans (CSPGs). Oli-neu produced large amounts of tenascin-C (TN-C), DSD-1-PG/phosphacan, and NG2, correlating with its inhibitory properties. Upon treatment with chondroitinase ABC (ChABC), retinal axon growth was increased on CA, MG, and A7, in accordance with the degradation of inhibitory CSPGs. In contrast, inhibition exerted by Oli-neu or postnatal oligodendrocytes was not abolished. When the neurite growth promoting properties of TN-C were neutralized by the monoclonal antibody J1/tn2, retinal axon growth was clearly diminished on MG, indicating a dominance of the FNIII domain D of TN-C in this cell type. The results suggest that glial cells construct complex ECM structures with distinct properties ranging from promotion to inhibition of retinal axons, depending on their composition. Furthermore, inhibitory ECM may resist ChABC treatment in some situations.

The glia-derived extracellular matrix glycoprotein tenascin-C promotes embryonic and postnatal retina axon outgrowth via the alternatively spliced fibronectin type III domain TNfnD.

Tenascin-C (Tnc) is an astrocytic multifunctional extracellular matrix (ECM) glycoprotein that potentially promotes or inhibits neurite outgrowth. To investigate its possible functions for retinal development, explants from embryonic day 18 (E18) rat retinas were cultivated on culture substrates composed of poly-d-lysine (PDL), or PDL additionally coated with Tnc or laminin (LN)-1, which significantly increased fiber length. When combined with LN, Tnc induced axon fasciculation that reduced the apparent number of outgrowing fibers. In order to circumscribe the stimulatory region, Tnc-derived fibronectin type III (TNfn) domains fused to the human Ig-Fc-fragment TNfnD6-Fc, TNfnBD-Fc, TNFnA1A2-Fc and TNfnA1D-Fc were studied. The fusion proteins TNfnBD-Fc and to a lesser degree TNfnA1D-Fc were stimulatory when compared with the Ig-Fc-fragment protein without insert. In contrast, the combination TNfnA1A2-Fc reduced fiber outgrowth beneath the values obtained for the Ig-Fc domain, indicating potential inhibitory properties. The monoclonal J1/tn2 antibody (clone 578) that is specific for domain TNfnD blocked the stimulatory properties of the TNfn-Fc fusions. When postnatal day 7 retinal ganglion cells were used rather that explants, Tnc and Tnc-derived proteins proved permissive for neurite outgrowth. The present study highlights a strong retinal axon growth-promoting activity of the Tnc domain TNfnD, which is modulated by neighboring domains.

Biochemical studies on marine fish oil part-I: effects of fish oil and lipid lowering drugs on HDL/LDL cholesterol levels.

Omega-3 fatty acids present in fish oil are potent cholesterol lowering agents. This fact has drawn our attention to investigate their effects alone and in combination with competitive inhibitors, (hydrooxymethylglutaryl coenzume-A reductase). The naturally occurring omega-3 fatty acids i.e., polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fish oil have been proved as anticholesterolemic agents. In order to observe their actions as lipid lowering agents, the present study has been carried out which deals with the synergistic effect of fish oil with that of Lovastatin and Gemfibrozil.

Pre- and postsynaptic responses to 1-(1-naphthylpiperazine) following adaptation to stress in rats.

In view of a role of pre- and postsynaptic serotonin (5-hydroxytryptamine; 5-HT) receptors in adaptation to stress, effects of 1-(1-naphthylpiperazine) (1-NP) were compared in unrestrained and repeatedly restrained adapted rats. In the first part of the study, effects of various doses (1.0-15 mg/kg ip) of 1-NP were monitored on brain 5-HT metabolism (presynaptic response) and on the activity (postsynaptic response) of rats in an activity cage to which the rats were habituated before the drug administration. The drug injected at doses of 2.5-15.0 mg/kg increased motor activity and decreased brain 5-hydroxyindoleacetic acid (5-HIAA) concentration in a dose-dependent manner. In the second part of the study, rats were restrained on wire grids 2 h/day for 5 days. First-day episode of 2-h restraint decreased 24-h cumulative food intake, water intake and growth rate. The decreases attenuated following second-, third- and fourth-day episodes of 2-h restraint were not observed following fifth-day episode of 2-h restraint stress, suggesting adaptation to the stress schedule has occurred. Serotonergic and motor responses to 1-NP in unrestrained and repeatedly restrained adapted rats were compared by injecting the drug at a dose of 5 mg/kg, a dose that above results suggested would not produce maximal effects on 5-HT metabolism or motor activity. Administration of 1-NP at a dose of 5 mg/kg increased motor activity and decreased brain 5-HIAA concentration in unrestrained and repeatedly restrained adapted rats. Increases of motor activity were much greater in repeatedly restrained adapted than unrestrained rats. Decreases of 5-HIAA concentration were comparable in the two groups. The results are discussed in the context of an increase in the effectiveness of postsynaptic 5-HT-1A and 5-HT-1B receptors and a decrease in the effectiveness of presynaptic 5-HT-1A (somatodendritic) and 5-HT-1B (terminal) receptors following adaptation to stress. It is suggested that these changes of receptor responsiveness might help coping with stress demand to produce adaptation to stress.