B. Dhawan

... Pretreatment by Gnawing Apomor-Amphet-~ethylpheni-(mg/kg ip) ehallange after phine amine date h gnawing gnawing gnawing Chlorpromazine (30) 1 -- -- + ... 191), 103--199 (1966). - - - Udsen, P.: Adrenergic mechanisms and amphetamine induced abnormal behaviour. ...

The study was undertaken to evaluate the role of nitric oxide (NO) in pretectal (PTN)-induced analgesia in rats. Microinjection of varying concentrations of L-arginine (1 nM to 1 microM) produced a quick, long-lasting and concentration-dependent analgesic response, whereas similar concentrations of D-arginine failed to produce analgesia. Moreover pretreatment with N-nitro-L-arginine methyl ester (L-NAME, 1 microM) significantly prevented L-arginine induced analgesia. Further, pretreatment of animals with methylene blue, a known guanylate cyclase inhibitor also prevented the development of analgesia. Our study suggests that L-arginine caused production of NO, which in turn activates pretectal analgesic system involving cyclic GMP.

Role of histaminergic mechanisms in the regulation of blood-brain barrier (BBB) was assessed in dog. Histamine increased the entry of sodium fluorescein from the blood to the cerebrospinal fluid (CSF) in a dose-dependent manner. Histamine receptor antagonists, mepyramine (H1) and metiamide (H2) per se did not affect the entry of dye in the CSF. Mepyramine failed to affect the change induced by histamine whereas metiamide completely blocked the histamine-induced entry of sodium fluorescein in CSF. 2-Methyl histamine, a specific H1-agonist, did not affect the barrier permeability. However, 4-methyl histamine, a specific H2 receptor agonist significantly increased the permeability of BBB. This increase was blocked by metiamide. Forskolin, a stimulant of adenylate cyclase, also increased the entry of dye in the CSF which could be significantly blocked by metiamide. It is concluded that histamine increases the permeability of BBB by affecting H2-receptors linked to adenylate cyclase.

1. Jpn J Pharmacol. 1974 Feb;24(1):5-13. Pharmacological profile of a new cyclohepten sympathomimetic agent, compound 70-352. Singh GB, Srimal RC, Dhawan BN. PMID: 4545932 [PubMed - indexed for MEDLINE]. Publication Types: In Vitro. MeSH Terms. ...

... Pharmacology of diferuloyl methane (curcumin), a non-steroidal anti-inflammatory agent* R. C. SRIMAL AND B. N. DHAWAN Division of Pharmacology, Central Drug Research Institute, Lucknow-1, India ... It has been widely used in indigenous medicine (Nadkarni, 1954). ...

Summary Effect of ??-methylnoradrenaline (??-MNA) on the hypothalamic, medullary and spinal vasomotor loci in anaesthetised cats was studied. ??-MNA (2???10 ??g icv or 0.5???1.0% topical) inhibited the excitability of hypothalamic as well as medullary vasomotor loci. It ...