RESUMEN
The article concentrates on representatives of voltage-gated calcium ion-channels that are present in practically all cells. Considered are the activation and inactivation processes of calcium channels and their molecular mechanisms. The review represents modem classification of voltage-gated calcium channels, draws parallels with the earlier classifications and discusses calcium currents going through various calcium channels. Presented are the genetic, molecular-biological, bio-physical, physiological and pharmacological information for each type of the ten known voltage-gated calcium channels.
Asunto(s)
Canales de Calcio/clasificación , Canales de Calcio/metabolismo , Activación del Canal Iónico , Animales , Canales de Calcio/genética , Humanos , Modelos BiológicosRESUMEN
The article concentrates on representatives of voltage-gated calcium ion channels that are present in practically all cells. Regarded is the molecular arrangement of a voltage-gated calcium channel that consists of pore forming trans-membrane alpha1 subunit and auxiliary alpha2delta-, beta-, and gamma-subunits. Under discussion are the structure and functions of each subunit. The principles of subunits interaction are considered. The research represents modern classification of voltage-gated calcium channels, draws parallels with the earlier classifications and discusses calcium currents going through various calcium channels. Considered are the problems of regulating the activity of voltage-gated channels by proteinkinases. The issues of blockers and activators of voltage-gated calcium channels are brought up. The article gives a detailed analysis of the mechanisms of voltage-gated calcium channels selectivity. The molecular organization of the selectivity filter is considered. Presented are the basic theories of permeability of voltage-gated calcium channels.
Asunto(s)
Canales de Calcio/química , Canales de Calcio/fisiología , Secuencia de Aminoácidos , Animales , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/clasificación , Canales de Calcio/efectos de los fármacos , Canales de Calcio Tipo L/genética , Membrana Celular/química , Humanos , Datos de Secuencia Molecular , Proteínas Quinasas/metabolismo , Alineación de SecuenciaRESUMEN
Stimulation of alpha-adrenoceptors was simulated by intraarterial injection of 0.6 mmol CaCl2 in acute experiments on resting muscles of the dog hind leg. It has been demonstrated that alpha-adrenergic stimulation of metabolism in skeletal muscles has a vasodilative effect in the muscle-supplying vessels. It has been also shown that imitation of alpha-adrenergic stimulation effect by intraarterial injection of CaCl2 causes Ca- and alpha-adrenergic-dependent vasodilative reactions. It is suggested that disturbance of vasodilative effects caused by alpha-adrenergic stimulation in the effector tissues, counteracting the direct constrictive alpha-adrenoceptor effect in the smooth muscle cells of the vessel wall, can lead to systemic impairment of the vascular tone.