Cholinergic muscarinic antagonists, atropine (1-5 mg/kg) and scopolamine (0.1-0.5 mg/kg) produced learning and memory deficits in step-down passive avoidance task paradigm in mice. NMDA-receptor antagonist (noncompetitive), MK 801 (0.1 mgikg) produced complete disruption of acquisition and retention, however, lower doses (0.025-0.05 mg/kg) showed improvement in retention parameters. Scopolamine potentiated memory disruptive effects of MK 801 (0.05 mg/kg). Combined administration of MK 801 (0.01 mg/kg) and scopolamine (0.3 mg/kg) - induced deficits were not reversed by physostigmine in step-down passive avoidance paradigm. Piracetam and aniracetam decreased number of mistakeson step-down task in scopolamine -treated and-untreated mice. These agents also showed reduction in shortened transfer latency (TL) on elevated plus-maze apparatus. The effect was reversed by MK 801 and scopolamine, both in rats and mice. Captopril (30 mg/kg) and enalapril (30 and 60 mgikg) attenuated scopolamine- induced deficits on step-down task paradigm, but not on elevated plus maze in rats and mice. The effects were being comparable to piracetam. However, captopril at lower doses (5-15 mgikg) did not show impairment of latency in reaching shock free zone (SFZ), unlike enalapril and prove to be more potent than enalapril on both paradigms. The results suggested a unidirectional pattern of activity of NMDA- and cholinergic- antagonism in the bahavioural expression of amnesia. Captopril was found to be more potent than enalapril in improving retention or consolidation phase of memory, the effect com-parable to nootropics, and proposed to involve central cholinergic and NMDA receptor modulation.

The effect of fluvalinate (15 mg/kg, i.p) on pentobarbitone induced hypnosis and spontaneous locomotor activity in mice revealed pronounced CNS depressant effect of the compound. It produced negative inotropic and chronotropiceffects on the isolated frog heart. Spontaneous motility of isolated chicken ileum was reduced by fluvalinate in dose dependent manner. Fluvalinate (15 mg/kg, i.p) treatment for 15 days resulted in significant reduction in total leucocyte and absolute lymphocyte count. The test compound when administered for 15 days @ 15 mg/kg/day i.p., produced hepato-nephro toxicity and mild peripheral disintegration of the lymphoid nodules in spleen.

The effects of verapamil and cyproheptadine in combination with chloroquine were examined against P.falciparum in vitro. Verapamil at 0.3-4.0 x 1O-6 mol/L blood potentiated the effects of chloroquine against chloroquine sensitive and chloroquine resistant isolates of P. falciparum in vitro. Verapamil acts both on early and late developmental stages of the parasite. Cyproheptadine in the conc. range of 0.6-2.4 x 10-6 mol/L blood potentiated the effects of chloroquine against chloroquine sensitive and resistant P. falciparum isolates. The combination of chloroquine and cyproheptadine may be of value and further studies seem to be justified.

Effect of Ocimum sanctum leaf extract was studied on paracetamol induced hepatic damage in rats. O.sanctum was found to protect the rats from hepatotoxic action of paracetamol as evidenced by significant reduction in the elevated serum enzyme levels. Histopathological studies showed marked reduction in fatty degeneration in animals receiving O.sanctum along with paracetamol as compared to the control group. It is stipulated that the extract treated group was partially protected from hepatic cell damage caused by' paracetamol.

The plasma disposition biodistribution and dosage regimens of gentamicin were studied in rabbits tollowing i.v. administration (4 mg/Kg). The distribution and elimination half-life values were calculated to be 0.38ñ 0.07 and 2.88ñ 0.33 h, respectively. The concentration of gentamicin was found to be highest in kidneys, both at 10 min and 1 h while adrenals revealed absence of the drug. Based on kinetic parameters, satisfactory i.v. dosage regimens of gentamicin in rabbits would be 10.02 and 8.71 mg/Kg as the loading and maintenance doses, respectively, to be repeated at 8 h intervals.

Pulmonary function tests [forced expiratory volume (FEVl) and peak expiratory flow rate (PEFR)] were conducted on healthy and non-smoking volunteers of either sex in Kashmiri population. PEFR and FEVI values of Kashmiri men were significantly higher than women. PEFR values of men and women population were significantly lower than healthy Western men and women whereas the FEVl values were not different from the reference standards.

A series of isodithiobiurets and 1,2,4-dithiazolines were synthesised and tested for their anticonvulsant and hypnotic activity. They showed significant activity against maximal electroshock seizure and also exhibited protection against metrazol and strychnine induced seizures. All the compounds of the series except Id, 1-diphenyl-5-m-chlorophenyl-2-S-ben-zyliso- 4-thiobiuret showed hypnotic activity.

The ocular hypotensive effect of a single topical application of verapamil was studied in albino rabbits. In normotensive rabbits, after base line measurement of intraocular pressure (IOP) with applanation tonometer, 30 'l drops of verapamil in the concentration of 0.125% was instilled in one eye while contra-lateral eye received the vehicle and served as control. The IOP measurements were taken at 30 min., 2, 4 and 8 hrs. The onset of pressure lowering effect was observed at 30 minutes, with a peak effect at two hours and persisted up to 8 hrs. The hypotensive effect of verapamil was also studied after water loading in twelve rabbits. The reduction of pressure was more marked (6r1.20 vs 4ñ 0.14 mm Hg) in water loaded rabbit's eyes as compared to normotensive eyes which was statistically significant (P < .001) when compared with base line values and with the contralaterarcontrol eyes.

The effect of 'Placentrex',a human placental extract, on glucose-6- phosphate dehydrogenase (GGPDH) activity in tissues like liver, kidney and brain of rats were studied. Single administration of 'Placentrex' produced a significant reduction in G6PDH activity at the dose of 0.4 ml/100 g body weight in all the tissues under observation. Its inhibitory effect has been found to be increasing with increased doses. It is concluded that long term use of 'Placentrex' may lead to deleterious effect.

Histamine produced concentration-dependent contraction of isolated longitudinal smooth muscles of chicken crop. Histamine-induced contractions were antagonized non-competitively by atropine, hexamethonium, cocaine, methysergide, indomethacin and verapamil. Physostigmine slightly potentiated the excitatory action of histamine. Theophylline did not produce any appreciable effect on histamine response. These results indicate that histamine exerted its excitatory action by involving a number of mechanisms.

Oral submucous fibrosis, an insidious chronic precancerous condition of oral cavity chiefly occurs in the Indian subcontinent. It manifests as stiffness of oral mucosa, trismus, burning sensation and inability to eat. lnj. Placenta extract was given locally and effects were monitored in reducing the severity of the disease. There was significant improvement in mouth opening, colour of oral mucosa, burning sensation, and reduction of fibrous bands.