Modulation of G-protein expression by the angiotensin converting enzyme inhibitor captopril in hearts from spontaneously hypertensive rats. Relationship with adenylyl cyclase

We have recently shown an enhanced expression of Gi alpha-2 and Gi alpha-3 at protein and mRNA levels and their relationship with adenylyl cyclase regulation in hearts and aorta from spontaneously hypertensive rats (SHR). The present studies were undertaken to examine if the antihypertensive action of captopril, an angiotensin I converting enzyme (ACE) inhibitor, is associated with the interaction and modulation of G-proteins and adenylyl cyclase activity. SHR and age-matched WKY were divided into two groups. One group of rats received captopril (10 mg/kg body weight) intravenously, whereas the other group received only vehicle (0.9% saline). The levels of Gi alpha-2 and Gi alpha-3 proteins were determined by immunoblotting technique using specific antisera against these proteins. The levels of Gi alpha-2 and Gi alpha-3 proteins were significantly enhanced in hearts from SHR as compared to WKY and captopril treatment restored the enhanced levels of Gi alpha-2 and Gi alpha-3 observed in SHR by about 70% to 80% towards WKY control rats. However, captopril slightly decreased the levels of Gi alpha 2 and Gi alpha 3 protein in normotensive WKY. In addition, the diminished stimulation of adenylyl cyclase by isoproterenol, glucagon and N-ethyl carboxamide adenosine and enhanced inhibition by inhibitory hormones such as C-type natriuretic peptide and angiotensin II observed in SHR was restored significantly by captopril treatment. These results suggest that one of the mechanisms by which captopril lowers the blood pressure may be due to its ability to modulate the levels of G-proteins and adenylyl cyclase activity.

Vanadium salts stimulate mitogen-activated protein (MAP) kinases and ribosomal S6 kinases

Effect of several vanadium salts, sodium orthovanadate, vanadyl sulfate and sodium metavanadate on protein tyrosine phosphorylation and serine/threonine kinases in chinese hamster ovary (CHO) cells overexpressing a normal human insulin receptor was examined. All the compounds stimulated protein tyrosine phosphorylation of two major proteins with molecular masses of 42 kDa (p42) and 44 kDa (p44). The phosphorylation of p42 and p44 was associated with an activation of mitogen activated protein (MAP) kinase as well as increased protein tyrosine phosphorylation of p42mapk and p44mapk. Vanadium salts also activated the 90 kDa ribosomal s6 kinase (p90rsk) and 70 kDa ribosomal s6 kinase (p70s6k). Among the three vanadium salts tested, vanadyl sulfate appeared to be slightly more potent than others in stimulating MAP kinases and p70s6k activity. It is suggested that vanadium-induced activation of MAP kinases and ribosomal s6 kinases may be one of the mechanisms by which insulin like effects of this trace element are mediated.

Diabetic retinopathy: a clinical study with special reference to fluorescein angiography

The present study was conducted on 25 patients with Diabetes Mellitus (DM) having positive indication of diabetic retinopathy on ophthalmoscopic examination. The patients were examined clinically, ophthalmoscopically and with Fluorescein Angiography (FA). It was found that the maximum number of patients with retinopathy were in their 5th and 6th decade and that retinopathy was more common in Non Insulin dependent diabetics (NIDDM) than Insulin dependent Diabetics (IDDM). It was also seen that retinopathy takes longer time to develop in IDDM patients (16.37 years vs 11.7 years). Proliferative diabetic retinopathy was more common with patients having poor glycemic control and in IDDM patients. FA was very helpful in detecting microaneurysms and for exact localization of neovascularization, and other microangiopathic lesions as well as for permanent record.

Anatomical basis for the clinical application of the arterial supply of musculus pectoralis major

The pattern of arterial supply to the various parts (clavicular, sternocostal and aponeurotic) of the pectoralis major muscle was studied in 7 cadaver dissections and 10 angiograms by injecting a radio-opaque substance. Three main arteries supplied the muscle, i.e. the pectoral branch of the thoracoacromial trunk (TAT-PB), the lateral thoracic artery and the perorating branch of the internal thoracic artery, supported by other branches of the TAT and the superior thoracic artery. It is observed that the TAT-PB, a chief vascular pedicle, anastomoses freely with other arteries and supplies most parts of the muscle. The present study is mainly focussed on the exclusion of the chief vascular pedicle of muscle to eliminate the confusion of previous studies and prevent the unnecessary hindrance and complications of the muscle flap.

Paradoxical approach to the management of faecal incontinence in normal children

Three children with faecal incontinence, in whom conventional treatment had failed, were managed with a regimen that focuses on the symptoms and present behaviour. It is short term and uses a paradoxical approach.