RESUMO
The spontaneous isometric developed tension (IDT), the synthesis and release of prostaglandins (PGs) into the incubating medium and the metabolism of triglycerides (TGs) in uterine strips isolated from controls and chronic ethanol fed rats, were studied. In order to observe how the uterus of rats fed alcohol reacts during a situation of metabolic emergency, the above mentioned studies were done in the presence or in the absence of glucose in the incubating medium. The decrement of IDT as time progressed was significantly greater in strips obtained from rats which had been drinking 20% ETOH than in controls. Nevertheless, the absolute magnitude of the initial IDT was similar in both groups. On the other hand, the decline of the frequency of contractions (FC) of uterine strips isolated from controls and from ETOH-exposed rats, after 60 min of spontaneous activity was similar. When the uterine strips isolated from ETOH-exposed and from control rats were suspended in glucose-free solution they exhibited the same decrement of IDT and FC after 60 min of activity. The basal release of PGE1 and PGE2 was similar in control tissues incubated in medium containing glucose, but the output of PGE2 was significantly smaller than that of PGE1 in uterine strips isolated from ETOH-exposed rats. The production of PGE1 and PGE2 by uteri suspended in glucose-free medium was similar in control preparations. On the contrary the release of both PGs differs in uterine strips from ETOH-exposed rats, i.e. the output of PGE2 was significantly smaller than in controls and the release of PGE1 increased around 4-fold in comparison with controls.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Alcoolismo/fisiopatologia , Prostaglandinas/biossíntese , Triglicerídeos/metabolismo , Útero/fisiopatologia , Alcoolismo/metabolismo , Alprostadil/biossíntese , Alprostadil/metabolismo , Animais , Dinoprostona/biossíntese , Dinoprostona/metabolismo , Feminino , Técnicas In Vitro , Prostaglandinas/metabolismo , Ratos , Ratos Endogâmicos , Contração Uterina , Útero/metabolismoRESUMO
Rat pups were treated with monoamine uptake inhibiting antidepressant drugs, desipramine, imipramine or nomifensine (5 mg/kg) during the second and third postnatal weeks, and their later behavioral "despair," measured by Porsolt's swim test, was examined. At the age of two months, the desipramine-treated rats showed lengthened immobility in the swim test, and thus probably increased behavioral "despair." They also responded to 1 g/kg alcohol by shortening the immobility to the level of control rats. Neonatal treatment with either imipramine or nomifensine did not affect the swim test behavior. The results suggest that a low, stimulatory dose of alcohol was able to reverse the lengthened immobility in the swim test of rats treated with desipramine during the early postnatal period.
Assuntos
Antidepressivos/farmacologia , Depressão/psicologia , Etanol/farmacologia , Animais , Animais Recém-Nascidos , Desipramina/farmacologia , Imipramina/farmacologia , Masculino , Atividade Motora/efeitos dos fármacos , Nomifensina/farmacologia , Ratos , Ratos EndogâmicosRESUMO
The generation and output of prostaglandins (PGs) E2 and F2 alpha into the solution suspending uterine segments from ethanol (ETOH)-fed diestrous rats and the activity of 15-OH-PG-dehydrogenase (PGDH) in uteri at diestrus, were explored and compared with normal-fed controls. Animals were fed with ETOH (35% of the total calories in a liquid diet) during 20 days before sacrifice. Paired normal-fed controls were given isocaloric quantities of dextrimaltose. It was observed that the uterine outputs of PGE2 and of PGF2 alpha into the suspending solution, were significantly greater in the ETOH group. On the other hand, the PGDH activity for PGE2 in control uterine tissue, was significantly smaller than the activity detected in preparations from animals fed with the chronic ETOH diet. Results are discussed in terms of possible mechanisms for the action of ethanol, either on the release of PG fatty acid precursors (activation of phospholipase A2) or on the activity of PG synthesizing enzymes. Inasmuch as in the ETOH-fed group uterine PGDH activity was greater, rather than diminished, the possibility of a reduced catabolism accounting for the augmentation of PGs in the suspending medium, does not appear feasible. In fact, results suggest that the real magnitude of higher PG generation and release is even greater than that disclosed by the present study. The finding that chronic ethanol consumption augments PG production, appears relevant, in view of the unique roles played by these eicosanoids in parturition and in the development of fetuses.
Assuntos
Dinoprostona/biossíntese , Etanol/toxicidade , Hidroxiprostaglandina Desidrogenases/metabolismo , Útero/metabolismo , Animais , Diestro , Feminino , Ratos , Ratos Endogâmicos , Útero/enzimologiaRESUMO
Dose-response curves for norepinephrine (NE), dopamine (DA) and 2-bromo-alpha-ergocryptine (BEC) in the isthmic and ampullary regions isolated from proestrous sow oviducts, were drawn. NE, DA and BEC depressed the contractile activity of ampullary segments in dose-dependent fashion. In the isthmic region, NE induced a dose-related stimulation whereas DA and BEC evoked relaxation. Propranolol (10(-6)M) did not modify significantly the effect of DA on the ampulla, whereas spiperone, chlorpromazine and haloperidol, shifted to the right DA dose-response curves. Haloperidol and spiperone were able to partially antagonize responses to DA of the isthmus. The catecholamine contents of the ampullary (a) and isthmic (i) regions of sow oviducts during proestrus (P), estrus (E) and metestrus (M) proved to be quite different and differently affected by the variations of the sex cycle: NE, DA and epinephrine (EPI) in (i) higher than in (a); NE in (i) and (a) during M higher than during E; NE in (i) lower during E than during P. The probable presence of specific dopamine receptors in sow oviducts as well as their eventual role in modulating tubal motility are discussed in this paper.
Assuntos
Dopamina/fisiologia , Tubas Uterinas/fisiologia , Animais , Feminino , SuínosRESUMO
The release of 3H-catecholamines evoked by Black Widow spider venom gland extract (BW-GE) has been studied in the isolated rat hypothalamus (HT), occipital cortex (OC), preloaded with 3H-noradrenaline, and isolated caudate nucleus (CN) preloaded with 3H-dopamine. The BWGE at a concentration of 0.04 gland/ml increased significantly 3H-output in isolated slices of rat HT, OC and CN. This effect was markedly depressed when control calcium concentration in the medium (1.68 mM) was reduced (0-0.56 mM) or enhanced (3 mM), as well as in the presence of an organic Ca2+ antagonist, verapamil (10 microM), or ionophore A 23187 (40 microM), a substance that increases the influx of calcium into the cell. Morphine (up to 0.4 mM) evoked no effect upon 3H-noradrenaline release induced by BWGE. Morphine (10 microM), but not ionophore A 23187 or high Ca2+ (3 mM), reduced 3H-noradrenaline release induced by 20 mM K+. Low Ca2+ and verapamil produced similar effects than those observed for BWGE. Our results demonstrate differences between BWGE and potassium stimuli, and indicate that BWGE releases 3H-catecholamines by a calcium dependent process.
Assuntos
Venenos de Artrópodes/farmacologia , Cálcio/metabolismo , Catecolaminas/metabolismo , Núcleo Caudado/metabolismo , Córtex Cerebral/metabolismo , Hipotálamo/metabolismo , Venenos de Aranha/farmacologia , Animais , Viúva Negra , Calcimicina/farmacologia , Estimulação Elétrica , Masculino , Potássio/metabolismo , Ratos , Ratos Endogâmicos , Trítio/metabolismo , Verapamil/farmacologiaRESUMO
The release of 3H-catecholamines evoked by Black Widow spider venom gland extract (BW-GE) has been studied in the isolated rat hypothalamus (HT), occipital cortex (OC), preloaded with 3H-noradrenaline, and isolated caudate nucleus (CN) preloaded with 3H-dopamine. The BWGE at a concentration of 0.04 gland/ml increased significantly 3H-output in isolated slices of rat HT, OC and CN. This effect was markedly depressed when control calcium concentration in the medium (1.68 mM) was reduced (0-0.56 mM) or enhanced (3 mM), as well as in the presence of an organic Ca2+ antagonist, verapamil (10 microM), or ionophore A 23187 (40 microM), a substance that increases the influx of calcium into the cell. Morphine (up to 0.4 mM) evoked no effect upon 3H-noradrenaline release induced by BWGE. Morphine (10 microM), but not ionophore A 23187 or high Ca2+ (3 mM), reduced 3H-noradrenaline release induced by 20 mM K+. Low Ca2+ and verapamil produced similar effects than those observed for BWGE. Our results demonstrate differences between BWGE and potassium stimuli, and indicate that BWGE releases 3H-catecholamines by a calcium dependent process.