The effect of chlorpromazine pretreatment on the vascular resistance in kidneys following warm ischaemia

Effect of chlorpromazine on sympathetic neuroeffector transmission in the rabbit isolated pulmonary artery and aorta

1. The effects of chlorpromazine on sympathetic neuroeffector transmission have been studied in the rabbit isolated pulmonary artery and aorta. 2. Chlorpromazine (10(-8)-10(-5) M), prazosin (10(-9)-10(-7) M) and phentolamine (3 x 10(-8)-3 x 10(-5) M) decreased the contractions of pulmonary artery evoked by electrical field stimulation (150 pulses; 3 Hz). The rank order of inhibitory potency (ID50) was prazosin greater than chlorpromazine greater than phentolamine. 3. Rauwolscine (3 x 10(-9) M-4 x 10(-6) M) enhanced the neurogenic response by up to 201%. However, higher concentrations (6 x 10(-6)-3 x 10(-5) M) reduced the contractions evoked by transmural stimulation. 4. The inhibitory effect of prazosin (10(-6) M) was reversible, while that of chlorpromazine (10(-8) M) was not. 5. Chlorpromazine (10(-8)-10(-4) M), desmethylimipramine (3 x 10(-9)-10(-5) M), cocaine (10(-7)-3 x 10(-4) M) and phentolamine (10(-5)-3 x 10(-4) M) reduced the accumulation of [3H]-noradrenaline ([3H]-NA, 10(-8) M) by aorta. The rank order of inhibitory potency (ID50) was: desmethylimipramine greater than chlorpromazine greater than cocaine greater than phentolamine. Prazosin (10(-7)-10(-5) M) and rauwolscine (10(-8)-10(-4) M) did not reduce [3H]-NA accumulation. 6. Chlorpromazine (10(-8)-10(-6) M) and prazosin (3 x 10(-9)-10(-7) M) antagonized the contractions of aorta evoked by exogenous noradrenaline (10(-9)-3 x 10(-4) M) and phenylephrine (10(-9)-3 x 10(-3) M). The pA2 values for chlorpromazine on the alpha 1-adrenoceptors were 8.24 (noradrenaline) and 8.27 (phenylephrine). The corresponding values for prazosin were 8.64 and 8.57, respectively. 7. It is concluded that chlorpromazine and prazosin are potent inhibitors of postsynaptic alpha 1-adrenoceptors. Chlorpromazine and phentolamine, unlike prazosin and rauwolscine, are also inhibitors of Uptake.

Effects of chlorpromazine on ischemic rat kidney: a functional and ultrastructural study

The effects of chlorpromazine, an agent with inhibitory effects of calcium influx, phospholipase activation, and Na-K-ATPase, on preserving renal function and proximal tubular ultrastructure were evaluated in renal ischemia. After right nephrectomy chlorpromazine (0.025 mg) or 1 ml of 0.9 per cent saline was selectively administered to the rat kidney immediately prior to a sixty-minute occlusion of the remaining renal artery. Pretreatment with chlorpromazine resulted in a significant attenuation in the rise in postischemic serum creatinine. Hypothermia of the kidney during ischemia provided an additional protective effect. Electron microscopic study of the proximal convoluted tubule demonstrated that the structural damage was less severe in chlorpromazine-treated rats and virtually complete preservation of a normal ultrastructure was observed when hypothermia was added.

Effects of verapamil on preservation of renal function after ischemia: functional and ultrastructural study

The effects of hypothermia and verapamil, a calcium antagonist, on preventing renal damage after 60 minutes of ischemia were studied in rats. Hypothermia alone provided the best protection, and pretreatment with verapamil failed to afford protective effects in normothermic and hypothermic ischemia, findings further supported by electron microscopic studies.

Perfusion--fixation of human kidneys for ultrastructural analysis

Surgically removed human kidneys were fixed by vascular perfusion to improve the preservation of renal tissue and, in particular, the proximal tubules for electron microscopic analysis. Fifty kidneys with various pathologic changes were perfusion-fixed with glutaraldehyde under pressure control immediately after nephrectomy. A Tyrode solution containing a spasmolytic drug initiated the perfusion. The results demonstrate that large volumes of ultrastructurally well-preserved kidney tissue can be obtained in normal (nontumorous) parts of tumor kidneys as well as in kidneys with chronic nephropathy. Several factors improved the quality of fixation: (1) start of perfusion-fixation within 15 min after clamping of the renal vessels, (2) careful handling of the kidney during nephrectomy, (3) simultaneous clamping of the main renal vessels, and (4) employment of a spasmolytic drug. In comparison with tissue from immersion-fixed renal biopsies, perfusion-fixed kidneys represented an improved basis for ultrastructural investigations of normal or pathologically changed human kidney tissue.

The effect of chlorpromazine pretreatment on the vascular function of kidneys damaged by warm ischaemia and cold storage in Collins' solution

Vascular resistance was determined in 40 rabbit kidneys after graded warm ischaemia up to 60 minutes and preservation in Collins' solution for 24 and 48 hours. Half of the animals were treated with chlorpromazine 3.5 mg/kg before induction of the ischaemia. Vascular function was determined during short-term perfusion with TIS-U-SOL at 4 degrees C. The experiments showed that warm ischaemia of 30 and 60 minutes duration gave an increase in vascular resistance. The increase was, however, smaller in kidneys pretreated with chlorpromazine. Preservation in Collins' solution for 24 and 48 hours did not change this correlation. Determination of the weights and thereby formation of oedema showed that all kidneys preserved had a small increase in weight. No difference was found between pretreated kidneys and untreated kidneys. It is concluded that pretreatment with chlorpromazine is capable of diminishing vascular contraction during the warm ischaemic period and that preservation in Collins' solution for up to 48 hours does not alter this beneficial effect.

The effect of chlorpromazine pretreatment on renal function and pathology in kidneys damaged by warm ischaemia

The influence of chlorpromazine pretreatment on kidney function and survival after temporary occlusion of the renal artery was investigated. Three hours of clamping of the renal artery and contralateral nephrectomy was performed in a group of ten rabbits pretreated with 3.5 mg/kg chlorpromazine and compared with a previously published control group of untreated animals. Chlorpromazine pretreatment improved survival. The kidney function, estimated by serum-creatinine, showed an earlier onset of function and the surviving animals regained nearly normal function. Histological examination revealed mild to moderate ischaemic changes, whereas the control group showed more profound damages.

The effect of chlorpromazine and heparin pretreatment on kidney viability and function after warm ischaemic damage

The influence of chlorpromazine and heparin pretreament on kidney function and histology has been investigated in rabbit kidneys damaged by warm ischaemia. Three experimental groups were investigated. One in which animals were pretreated with heparin, one group pretreated with heparin and chlorpromazine, and one group without pretreatment. The left renal artery was temporarily clamped for 3 hours and the kidneys recirculated. After 2-3 weeks a delayed contralateral nephrectomy was made, and after another 2-3 weeks all kidneys were studied histologically. Kidney function was measured by determination of serum-creatinine. The experiments showed, that all animals survived with impaired renal function. Pretreatment with chlorpromazine and heparin did not affect the final results. Secerity of the ischaemic damage, histologically evaluated was the same in all groups.