Reference

Chronic antihypertensive treatment in the rat reverses hypertension-induced changes in cerebral blood flow autoregulation

Chronic antihypertensive treatment in the rat reverses hypertension-induced changes in cerebral blood flow autoregulation.Some chemicals with cas registry numbers like 484-23-1 and 50-55-5 are also used. Vorstrup, Sissel; Barry, David I.; Jarden, Jens Ole; Svendsen, Ulrik Gerner; Braendstrup, Otto; Graham, David I.; Strandgaard, Svend (Dep. Neurol., Rigshosp., Copenhagen, Den.). Stroke (Dallas), 15(2), 312-18 (English) 1984. CODEN: SJCCA7. ISSN: 0039-2499. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Cerebral flow (CBF) autoregulation was studied in renal hypertensive rats receiving chornic antihypertensive treatment (reserpine [50-55-5], dihydralazine [484-23-1], and hydrochlorothiazide [58-93-5] administered in the drinking water). Blood pressure fell rapidly to normotensive levels and remained so. Following 2 mo of antihypertensive treatment, the lower blood pressure limit of CBF autoregulation was studied during controlled bleeding. In age-matched untreated reanl hypertensive animals, the lower limit of autoregulation was in the mean arterial pressure range 90-109 mm Hg, as compared to 50-69 mm Hg in age-matched normotensive controls. In contradistinction to the untreated rats, the treated rats had a normal lower limit of autoregulation, i.e., 50-69 mm Hg. Apparently the reversal of the functional change in CBF autoregulation reflected reversal of hypertension-induced cerebrovascular hypertrophyl-hyperplasia. .

Liquid chromatographic determination of methyldopa and methyldopa-thiazide combinations in dosage forms

Liquid chromatographic determination of methyldopa and methyldopa-thiazide combinations in dosage forms. Ting, Susan (Food Drug Adm., Brooklyn, NY 11232, USA). J. Assoc. Off. Anal. Chem., 66(6), 1436-42 (English) 1983. CODEN: JANCA2. ISSN: 0004-5756. DOCUMENT TYPE: Journal CA Section: 64 (Pharmaceutical Analysis) Chromatog. on a mBondapak C18 column with 3% HOAc-MeOH (), theobromine internal std., and detection at 280 nm, was developed for the detn. of methyldopa (I) [555-30-6] in tablets and oral suspensions and combinations of I with hydrochlorothiazide (II) [58-93-5] or chlorothiazide (III) [58-94-6] in tablets. A mixt. of these 3 drugs was resolved in <8 min. Detector responses were linear for the following amts. (mg/mL) of drug injected: I 0.031-0.393, III 0.019-0.114, and II 0.004-0.083. Recoveries from com. dosage forms were 99.1-100.9% for I, 99.2-100.4% for III, and 100.0-101. 88620-56-8 and 6739-31-7 which are cas registry numbers of chemicals are mentioned.2% for II. Replicate injections of I, and II std. prepns. alone or in combination gave overall relative std. deviations of <1.6%. The results for I tablet by the proposed method agreed with those obtained by the USP XX method. The method detected as little as 0.6 mg/mL 3-O-methylmethyldopa [6739-31-7] and 0.5 mg/mL 4-amino-6-chloro-1,3-benzenedisulfonamide [121-30-2], which are sometimes found as contaminants of I and thiazides, resp. and resolved I from its methyldopa glucose adduct [88620-56-8], a substance found in I oral suspensions. .