The cardiovascular and respiratory effects of dermorphin (D) have been evaluated in freely moving or anesthetized normotensive and spontaneously hypertensive male rats. Intravenously or ...intracerebroventricularly administration of D produced arterial hypotension with sinus bradycardia and respiratory depression. Naloxone antagonized the effects of D. Atrial natriuretic antipeptide IgG reduced the cardiovascular responses without any significant modification of respiratory response. ICI 174864, naloxonazine and binaltorphimine did not reduce the cardiovascular and respiratory effects. In hypertensive rats D produced more intense and longer cardiovascular effects than those seen in normotensive animals. D effects involve the activation of mu and k opioid receptors for cardiovascular responses and mu 2 opioid receptors for respiratory depression without any significant effect on delta receptors. The release of atrial natriuretic peptide also appears to be involved in the cardiovascular effects of D.
The synthesis of beta-dialkylaminoethyl ethers (III a-f) and gamma-dialkylaminopropyl ethers (III g-l) starting from 1,3,3-trimethyl-5-(phenylmethylene)-2-oxabicyclo2.2.2octan-6- hydroxyimine (II) is ...described. beta-Diisopropylaminoethyl ether (III b) and gamma-piperidinopropyl ether (III i) showed an antiarrhythmic activity in rats similar to that of quinidine. Moreover, a number of ethers (III) showed weak hypotensive and bradycardic activity in rats and moderate infiltration anesthesia in mice.
Exposure to drugs during pregnancy can alter functional development of the vascular system. The present investigation was carried out in order to evaluate the effects of prenatal and postnatal ...exposure to Ca2+-antagonist (diltiazem, verapamil, and nimodipine) drugs on the development of rat vasomotor reactivity. Studies were carried out on pregnant female albino rats exposed from the first day of pregnancy until weaning to diltiazem and verapamil (6 and 24 mg/kg in their drinking water ad libitum) and nimodipine (3 and 12 mg/kg in their food ad libitum). After weaning, pups were exposed until the 60th day of age to the same treatment as their mothers were. Afterwards, pups from the 60th to 90th day of age were fed with a normal diet. In 30-, 60-, and 90-day-old conscious and anaesthetized pups, we evaluated the following: 1) systolic arterial blood pressure; 2) vasomotor responses elicited by various agents: L-noradrenaline (0.1, 1, and 5 micrograms/kg IV), L-isoprenaline (0.01, 0.1, and 1 micrograms/kg IV), and acetylcholine (0.01, 0.1, and 1 micrograms/kg IV) and by sinus-carotid baroreceptor stimulation; and 3) catecholamine, acetylcholinesterase, and adenosinase plasma levels. Prenatal and postnatal exposure to Ca2+-antagonist drugs significantly (P less than .05) decreased the pressor response to sinus-carotid baroreceptor stimulation and to L-noradrenaline and increased the hypotensive responses to L-isoprenaline and acetylcholine. Moreover, this type of treatment, although it induced a significant (P less than .05) decrease of catecholamine plasma levels, did not modify the acetylcholinesterase and adenosinase plasma levels in 30- and 60-day-old rats. On the 90th day of age, the evaluated parameters were not different from those of control rats. Our results showed that exposure to Ca2+ antagonists during pregnancy and the postnatal period may alter the functional development of rat vasomotor reactivity.
