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Biomedical subjects

S K Puri

Publications and source records attributed to S K Puri.

At least 109 records · Page 6Linked to original sources
PubMed1979

Circadian rhythm of cyclic nucleotide and GABA levels in the rat brain.

Daily variation in the levels of cyclic nucleotides and GABA was examined in seven brain regions of male Sprague-Dawley rats. Significant daily rhythm of cyclic AMP levels was found in the cerebellum and pons medulla oblongata. Circadian variation of cyclic GMP levels was found in the cerebellum, cerebral cortex, striatum, and hypothalamus. Daily variation of GABA levels was found in the pons medulla oblongata and striatum. Cyclic GMP in the pons medulla oblongata and GABA in the hypothalamus were found to exhibit ultradian variation of levels. These observed daily fluctuations of baseline levels should be considered when examining the duration of action of various drugs upon these substances.

Animals↗
PubMed1979

Schizontocidal activity of antibiotics against blood-induced Plasmodium gallinaceum infection.

Comparative studies on the blood schizontocidal activity of antibiotics against Plasmodium gallinaceum infection of chicks have shown that doxycycline, minocycline, demeclocycline, tetracycline and oxytetracycline possess high antimalarial activity as judged by suppression of parasitaemia and extension of survival period. Of these, demeclocycline, tetracycline and oxytetracycline were effective only at high dose level. Chloramphenicol, erythromycin and gentamicin were relatively inactive. Treatment in 5- to 6-day-old established infection of chicks has shown that doxycycline and minocycline are relatively more effective than oxytetracycline and tetracycline in controlling acute infection.

Administration, Oral↗
PubMed1976

Effect of epinephrine on cyclic AMP levels and adenylate cyclase and phosphodiesterase activities in control and antigen-sensitized guinea pig lungs.

Cyclic AMP levels and adenylate cyclase and phosphodiesterase activities were measured in control and ovalbumin-sensitized guinea pig lungs. Cyclic AMP levels were raised by epinephrine (0.01-10 mug/ml) in both control and sensitized lungs; the response being larger in the former group. Epinephrine (10(-9) -10(-6) M) stimulated adenylate cyclase in sensitized but had only a minimal effect in control preparations. Phosphodiesterase activities were equal in both groups. The hypersensitivity of adenylate cyclase response to epinephrine concurrent with diminished accumulation of cyclic AMP in sensitized guinea pigs indicate that antigen sensitization alters the response of the cyclic AMP system to epinephrine.

Adenylyl Cyclases↗
PubMed1976

Adenylate cyclase activity in heart and lung: effect of epinephrine and histamine in control and sensitized guinea pigs.

The effect of epinephrine and histamine on adenylate cyclase activity in lungs and hearts of control and ovalbumin-sensitized guinea pigs was investigated. Epinephrine at 10(-6) M concentration stimulated adenylate cyclase from both organs of the sensitized animals but had no effect on the enzyme from control tissues. At 10(-4) M, epinephrine stimulated equally the enzyme activity from the control and sensitized lungs and hearts. Histamine, 10(-6) and 10(-4), stimulated equally adenylate cyclase in tissues from both groups of animals. The results suggest that ovalbumin sensitization leads to hypersensitivity of the beta-adrenergic receptors to epinephrine without changing their sensitivity to histamine.

Adenylyl Cyclases↗