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Biomedical subjects

M I Titov

Publications and source records attributed to M I Titov.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Biochemical aspects of enkephalin participation in the regulation of adrenergic effects on myocardium].

Stable derivative of Leu enkephalin, intravenously administered into rabbits and rats, decreased the rate of activation of creatine phosphokinase, aspartate- and alanine transaminases as well as corrected hypomagnesemia and the deteriorations in blood plasma osmolarity caused by novodrin necrosis of myocardium. The data obtained suggest that enkephalins appear to influence the system of cyclic nucleotides in myocardium.

Alanine Transaminase↗
PubMed1983

Opiate binding sites and endogenous opioids in Bufo viridis oocytes.

Binding sites with high affinity for [3H]naloxone, but not for [3H]morphine and [3H] (D-Ala2, D-Leu5) enkephalin, have been found in membranes of Bufo viridis oocytes. The binding is reversible and saturable. Bound [3H]naloxone is easily displaced both by unlabeled naloxone and bremazocine, much worse by morphine and SKF 10,047; (D-Ala2, D-Leu5) enkephalin and beta-endorphin practically fail to displace [3H]naloxone. Scatchard analysis is consistent with the existence of two classes of binding sites with Kd 15 nM and 10(3) nM. The number of binding sites with high affinity for naloxone is 16 pmol/mg protein of homogenized oocytes which is 20-50-fold higher than in, toad or rat brain. Oocyte extract displaces [3H]naloxone bound with oocytes' membranes and inhibits electrically evoked contractions of the rabbit vas deferens. This inhibition is reversed by naloxone. It is suggested that compounds similar to opiate kappa-agonists exist in oocytes. It cannot be ruled out that they participate via specific receptors in the regulation of oocyte maturation and egg development.

Animals↗
PubMed1982

[Effect of leu-enkephalin and tyrosine on lymphatic and blood microvessels].

It has been found that neuropeptide leienkephalin and tyrosine occupying an N-end position in the peptide chain of leienkephalin are activators of the contractile activity of lymphatic microvessels of the mesentery. It is being attempted to obtain an even more active leienkephalin analogue by increasing the tyrosine content in its peptide chain.

Animals↗
PubMed1981

Enkephalins induce asymmetrical effects on posture in the rat.

Enkephalins when applied subarachnoidally induce hind limb postural asymmetry in rats with transected spinal cord. The effect is antagonized by naloxone. Methionine-enkephalin induces predominantly left limb flexions while leucine-enkephalin causes mostly right limb flexions. The data suggest an asymmetry existing in the enkephalinergic system in the rat spinal cord.

Animals↗
PubMed1981

[Effect of met- and leu-enkephalins and their synthetic analog on stimulation and acupunture analgesia].

Experiments on unrestrained rats were carried out to study the effect of intraventricularly injected met- and leu-enkephalins and their synthetic analog Tyr-dAla-Cly-Phe-NH2 on analgesia induced by electrical stimulation of the central gray. It was shown that subanalgesic doses of enkephalins and their synthetic analog facilitated the appearance of analgesic action on subthreshold antinociceptive-brain stimulation and potentiated the analgesic effect of threshold central gray stimulation. Subanalgesic and low analgesic doses of the peptides increased antinociceptive effect of electroacupuncture. The data obtained are discussed from the standpoint of the implication of the peptidergic mechanisms in the realization of acupuncture and stimulation analgesia.

Acupuncture Therapy↗
PubMed1981

[Effect of enkephalins on central processes regulating hemodynamics].

Intracisternal administration of leu- or met-enkephalins in a dose of 100 micrograms into unanesthetized cats evoked a short-lasting elevation of arterial pressure and tachycardia. After 1.5-2 minutes the blood pressure returned to normal and bradycardia developed (heart rate = 86 +/- 3.4% of initial). Alterations in the arterial pressure and heart rate were prevented by naloxon in a dose of 50-100 micrograms administered into the 4th ventricle. Leu-enkephalin inhibited the sensitivity of the baroreceptor reflex and increased by 69% the pressor reactions evoked by hypothalamus stimulation. Met-enkephalin was half as potent with respect to the baroreceptor reflex and exerted no effect on the hemodynamic reactions evoked by hypothalamus stimulation.

Animals↗
PubMed1981

[Effect of leu- and met-enkephalins on the brain's reinforcement systems].

Experiments on rats were made to study the effects of intracerebroventricular injection of met- and leu-enkephalins (ME and LE) during the reactions of self-stimulation and active avoidance (AA) of electrical stimulation of the central gray of the midbrain. Microinjections of LE in doses of 50-100 micrograms facilitated SS of the brain. ME in doses of 50-200 micrograms inhibited SS of the central gray. Both enkephalins inhibited AA reaction but this effect was more remarkable after LE injection. The effects of the enkephalins on SS and AA were reversed by naloxon.

Animals↗
PubMedDate not supplied

Met-enkephalin-induced release into the blood of a factor causing postural asymmetry.

Met- and Leu-enkephalin applied subarachnoidally into the rostral portion of a transected spinal cord (at the T6-T7 level) induce postural asymmetry of the hind limbs in rats, Met-enkephalin being predominantly responsible for the flexion of the right, and Leu-enkephalin of the left, hind leg. The blood serum of rats injected with Met-enkephalin contains a factor which, when administered subarachnoidally into the caudal portion of the transected spinal cord, is capable of inducing the hind limb postural asymmetry--predominantly, with the right leg flexion. This factor is inactivated by papain and differs from Met- and Leu-enkephalin in chromatographic properties. Apparently, Met-enkephalin induces the release of a peptide factor into the blood, from the brain or organs innervated by the neurons lying above the cut. It is then carried with the blood to the hind limbs and effects the hind limb postural asymmetry.

Animals↗