Biomedical subjects
Publications and source records attributed to S Dikstein.
GABA and its analogues were shown to activate the rabbit corneal endothelial fluid pump in the micromolar range. The stimulation was abolished by bicuculline and chlorpromazine, but not by picrotoxin.
Induced high intraocular pressure, lasting more than one hour, is described in the rabbit. We inject simultaneously inside aqueous humor Epsilon Amino Caproic Acid 5 mg and Thrombin 20 U.S.N.I.H. units. To avoid leakage of aqueous humor we make the injection though a nou-perforating corneal preplaced loep and sight the suture to close the track when injection needle is taken out. We assume that high intraocular pressure is induced by 1% Adrenaline, 2% Pilocarpine and 1% Guanethidine solutions dropped in the eye each 5 mn, beginning 15 mn before anterior chamber injection and lasting during all the experiment. We point out this fact as a proof of the suitability of this method.
Prevention of high blood pressure in uninephrectomized, DOCA-saline treated rats was observed after treatment with central tyramine precursors. We suggest that the high blood pressure is either due to relative lack of tyrosine, which might be caused by the hyperactivity of tyrosine hydroxylase, or to hypoactivity of the decarboxylase: in both cases the result is diminished tyramine synthesis.
Explore the source record for details and available documents.
Salt consumption was compared in two strains of rats, selected for their disparate proneness (strain "H") or resistance (strain "N") to Doca-salt hypertension. NaCl intake was similar in "H" and "N" rats prior to an following administration of Doca, while their respective blood pressures at the end of this experiment was 178 +/- 5mm Hg vs. 134 +/- 3 mm Hg. Thus, disparate responses of the blood pressure to Doca in the two strains cannot be ascribed to differences in salt intake. In another study, salt preference was tested in "H" and "N" rats by two-bottle self-selecting technique. Before Doca, saline preference in "H" rats averaged 60.3 +/- 5.8% of total daily fluid consumption, vs 18 +/- 4.2% in "N" rats. Following Doca treatment for 3 weeks the respective values were 96 +/- 1.7% vs 67 +/- 6.6%. Thus Doca treatment enhanced salt appetite in both strains, but salt preference remained significantly higher in the "H" rats. The increased susceptibility to hypertension and enhanced salt appetite in the "H" rat, corroborates similar reports in the Okamoto "SH" rat. In the Brookhaven "S" rat, however, susceptibility to hypertension is associated with salt avoidance. The conflicting data do not support a unified concept of a genetically determined link between salt appetite and proneness to hypertension.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
1. A technique for isolating and perfusing the rabbit cornea is described, which allowed its thickness to be continuously measured under the microscope. The reversal of thickness of the cold-swollen cornea on perfusion with various solutions at 37 degrees C was studied.2. It was found that only a combination of adenosine and glutathione was able to reliably reverse the thickness to its normal value. This mechanism is sodium, bicarbonate, and oxygen dependent. Inhibitors of glycolysis or electron transport stop the reversal process.3. The findings are consistent with a need for an ATPase but are not capable of distinguishing among several possibilities for its regulation.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.