Action of chlorpromazine. 3. Mitochondrial adenosine triphosphatase and the adenosine triphosphate-adenosine diphosphate exchange

Multifaceted effect of chlorpromazine in cancer: implications for cancer treatment

Since its discovery in 1951, chlorpromazine (CPZ) has been one of the most widely used antipsychotic medications for treating schizophrenia and other psychiatric disorders. In addition to its antipsychotic effect, many studies in the last several decades have found that CPZ has a potent antitumorigenic effect. These studies have shown that CPZ affects a number of molecular oncogenic targets through multiple pathways, including the regulation of cell cycle, cancer growth and metastasis, chemo-resistance and stemness of cancer cells. Here we review studies on molecular mechanisms of CPZ’s action on key proteins involved in cancer, including p53, YAP, Ras protein, ion channels, and MAPKs. We discuss common and overlapping signaling pathways of CPZ’s action, its cancer-type specificity, antitumorigenic effects of CPZ reported in animal models and population studies on the rate of cancer in psychiatric patients. We also discuss the potential benefits and limitations of repurposing CPZ for cancer treatment.

Muscle regeneration and mitochondrial calmitine increase in the dystrophic dy/dy mouse after intramuscular chlorpromazine injection

We studied the effect of chlorpromazine injection on the gastrocnemius muscles of C57BL/6J dy/dy dystrophic mice. Changes in mitochondrial calmitine concentrations and differences in microscopy studies, fibre typing and morphometry were compared in gastrocnemius muscles of dystrophic and control mice before and 2 and 21 days after injection. In both cases, calmitine reduction associated with muscle degeneration was observed 2 days after drug injection. Calmitine then increased, reaching a level at day 21 nearly identical to that of controls before injection. This increase was associated with muscle regeneration. These results clearly indicate that dystrophic mouse muscle can regenerate calmitine after drug-induced damage.

Mdx mouse skeletal muscle: could a mitochondrial factor be responsible for the absence of progressive necrosis?

We compared the myotoxic effect of chlorpromazine on mitochondria of gastrocnemius muscle in X-related muscular dystrophy (mdx) and control mice relative to changes in calmitine and calcium concentrations before and 3 and 6 days after a single injection of the drug. The results indicate that mdx mouse mitochondria are less sensitive to the myotoxic effect of chlorpromazine; calmitine and calcium binding were only slightly reduced compared to controls. Our observations indicate that the calmitine structure could differ in mdx and control mice with respect to calcium binding structures, and that the presence of calmitine in the mitochondria of mdx mouse skeletal muscle could explain why muscle degeneration does not occur in these animals. However, the muscles of patients with Duchenne muscular dystrophy (DMD) are lacking in calmitine and are subject to extensive progressive degeneration.

Effect of torbafylline on mitochondrial calmitine in mouse skeletal muscle regeneration after injection of a myotoxic drug

The effect of torbafylline, a xanthine derivative (Hoechst, Werk Albert, Wiesbaden, Germany), was tested relative to changes in degeneration and subsequent regeneration processes in mouse gastrocnemius muscle induced by a single injection of chlorpromazine, a myotoxic drug. These processes were monitored by measuring changes in calmitine, a mitochondrial protein. We determined in our previous work that calmitine concentration decreases during degeneration and progressively increases during regeneration. In this study, we compared effects in torbafylline-treated mice with those in control mice treated with saline solution. The results show that regeneration is much faster with torbafylline treatment. Calmitine is decreased and returns quickly to normal in torbafylline-treated mice as compared to those treated with saline solution. Torbafylline might thus prove effective in stimulating muscle regeneration in myopathy.

Changes in mitochondrial calmitine and calcium in rat denervated skeletal muscle after injection of a myotoxic drug, chlorpromazine

1. Calmitine and mitochondrial calcium were studied after injection of chlorpromazine into control and denervated gastrocnemius muscle in rat. 2. Calmitine decreased under the effect of chlorpromazine and then increased again. Regenerative capacity was more marked for denervated than control muscle. Calcium increased and then returned to its normal level in control muscle while remaining elevated in denervated muscle. 3. Thus, it would appear that calmitine synthesis can occur in the absence of innervation and that denervation, which probably causes disturbances in mitochondrial calcium regulation systems, may prevent total regeneration of muscle after an injury.

Chlorpromazine-induced cardiomyopathy in rats

We studied the chronic effects of chlorpromazine (CPZ) on the myocardium of rats using light and electron microscopy. Wistar strain rats were divided into two groups and given either normal saline or CPZ intraperitoneally at a dose of 5 mg/kg body weight/day for 30 consecutive days. Myocardial degeneration, atrophic muscle fiber, and myocardial fibrosis were observed by light microscopy in all CPZ-treated rats. Ultrastructural alterations of the myocardium were also found in all CPZ-treated rats. They consisted of contracted myofibers, mitochondriosis, degenerated mitochondria, dilated sarcoplasmic reticulum, and increased collagen fibers. However, no abnormal histologic or ultrastructural changes were observed in the normal saline-treated rats. We therefore conclude that a chronic administration of a sedative dose of CPZ causes myocardial damage in rats.

Effect of chlorpromazine on isolated rat hepatocytes

The effect of chlorpromazine hydrochloride (CPZ) (1-500 microM) on plasma membrane permeability and mitochondrial respiratory function of isolated rat hepatocytes was studied. The endogenous oxygen consumption stimulated by 1 mM succinate was increased significantly by 5 microM CPZ, whereas the ability to exclude trypan blue (TB) was decreased significantly by 100 microM CPZ. The release of a cytosomal enzyme, lactate dehydrogenase (LDH), was increased significantly by 50 microM CPZ, whereas the release of glutamic-opalacetic transaminase (GOT) was increased significantly by 100 microM. The endogenous oxygen consumption was decreased significantly by 150 microM CPZ. The respiration control ratio by 2 microM carbonylcyanide-m-chlorphenyl hydrazon (CCP) showed significant decreases at all concentrations of CPZ studied; and this might be attributable to the suppression by CPZ of the respiratory stimulation induced by CCP. The results indicated that CPZ at a low concentration (5 microM) first produced a significant change in plasma membrane permeability to low molecular substances such as succinate and then at higher concentrations (50-100 microM) produced significant release of the cytosomal and mitochondrial enzymes, LDH and GOT. They also indicated that the concentrations of CPZ which produced significant effects on respiratory function were higher (above 150 microM) than those which produced significant changes in plasma membrane permeability of hepatocytes.

Oxidized and reduced nicotinamide-adenine dinucleotide phosphate in tissue suspensions of rat liver

1. The concentrations of NADP and NADPH(2) in homogenates of rat liver (expressed as mug./g. wet wt. of tissue homogenized) were compared with values obtained from intact samples of liver taken from the same female rat. With 0.25m-sucrose alone as the suspending medium, or in combination with tris buffer or 0.01-0.1m-nicotinamide, considerable decreases in the sum of the NADP+NADPH(2) concentrations were occasionally observed during 30min. storage of homogenates at 0 degrees . However, addition of 0.5m-nicotinamide+5mm-tris buffer to 0.25m-sucrose for use as a suspending medium maintained the sum of the NADP+NADPH(2) concentrations in homogenates at the level found in intact tissue for at least 30min. at 0 degrees . 2. The effects of freezing intact tissue and homogenates in liquid nitrogen before the extraction of NADP and NADPH(2) were studied. Freezing alone appears to convert a significant amount (approx. 30%) of liver NADPH(2) into an equivalent amount of NADP in intact tissue. This is discussed in terms of the ;bound NADP' reported by Burch, Lowry & Von Dippe (1963). 3. The intracellular distributions of NADP and NADPH(2) in intracellular fractions of rat liver were studied by using a modified centrifuging scheme that allows extraction of the isolated fractions to be performed within 45min. of killing the animal. Approx. 50% of the total NADP+NADPH(2) was found in the large-particle fractions and the remaining 50% was mostly in the soluble fraction of the cell. 4. Further investigations are reported on the nature of ;bound NADP' in rat liver. Most of this material appears associated with the ;nuclear' (containing nuclei, debris, erythrocytes etc.) or large-mitochondrial fractions, or both, obtained by low-speed centrifuging of rat-liver homogenates. 5. Although in some experiments the variations produced in the concentration of NADPH(2) present in large-particle fractions were followed by similar changes in that of ;bound NADP', in other cases no such direct relationship was obtained. Addition of phenazine methosulphate, for example, consistently lowered the concentration of NADPH(2) yet raised the concentration of ;bound NADP' in rat-liver mitochondrial fractions.