Monoaminergic-peptidergic interactions in neuroregulatory control of the cephalic aorta in Sepia officinalis L. (cephalopoda)

Nitric oxide: a vasodilatatory mediator in the cephalic aorta of Sepia officinalis (L.) (Cephalopoda)

“…The drugs tested were applied to extended vessel segments or to vessels precontracted by a constant concentration of 5´10 A5 M dopamine (DA) (Ratiopharm), proven to be the most potent vasoconstrictory catecholaminergic agonist on the cephalic aorta of S. ocinalis (Schipp et al 1991). The following drugs, known to have de®ned eects on nitrergic mechanisms, were tested in constant or cumulatively increasing concentrations: (1) NO releasers: In addition, the following vasoactive agents were applied: acetylcholine (ACh; Sigma), muscarine (Sigma), FMRFamide (Sigma), tetraethylammonium (TEA; Merck, Darmstadt).…”

“…Before the pharmacological tests were started, the preparations were allowed to equilibrate for 120±180 min, until the resting tension curve had attained a constant value (for further details of the methods applied see Schipp et al 1991).…”

The cephalic aorta of Sepia officinalis (Cephalopoda, Dibranchiata): structural muscular specialisations of a high-pressure vessel

“…However, these occurred only in preparations with an intact tunica adventitia and tunica periadventitia where accompanying muscle fibres of the obliquely striated type are present along with nerves and vasa vasorum. They never occurred in pure tunica media muscle preparations without these peripheral layers (Schipp et al 1991).…”

“…The arrangement of actin and myosin filaments of the sarcomeres between lateral processes of one and the same z-patch cord, as well as the low number of sarcosomes, is in line with the relative slowness and limited contraction range of this muscle system. A high chronaxie and long-term contraction phases can be seen as physiological parameters of these particular tonic properties of the vessel (Shadwick and Gosline 1985a,b;Schipp et al 1991).…”

“…Because of the high blood pressure in the nearly closed circulatory system of dibranchiate cephalopods (Coleoida), the large arteries show many structural and functional analogies to vertebrate arteries (Barber and Graziadei 1967;Schipp 1987a,b;Schipp et al 1991). In particular, the tonic properties of the cephalic aorta of Coleoida have been compared with those of large "Windkessel" vessels of vertebrates (Shadwick and Gosline 1985a,b, 1987: aorta in Octopus dofleini Wulker, 1910.…”