Prolactin and propranolol prevent the suckling-induced inhibition of lactation in rabbits

Characteristics of suckling stimulation determine the daily duration of mother‐young contact and milk output in rabbits

“…Thus, the same trends in milk output were noted among them, that is, an increase, a plateau, and a decline in early-, mid-, and late lactation, respectively. These findings agree with the report that the suckling stimulation provided by ''old'' pups triggers mechanisms, which include a beta-adrenergic tone, that actively inhibit milk output Mena, Clapp, Aguayo, & Martínez de la Escalera, 1990). From our present findings, it is apparent that even a single ''old'' pup is capable of activating mechanisms that reduce milk production in late lactation.…”

Immunohistochemical Characterization of Sympathetic Chain Ganglia (SChG) Neurons Supplying the Porcine mammary Gland

“…These findings coincide with the results of similar studies carried out to determine the coexistence of various biologically active substances in neurons SChG supplying different target organs (Hill and Elde, ; Schotzinger et al., ; Zalecki, ). Earlier publication dealing with innervation of the mammary gland revealed that sympathetic nervous system is involved in the inhibition of milk ejection process (Mena et al., ; Eriksson et al., ; Morales et al., ,b; Wellnitz and Bruckmaier, ). This fact would confirm the belief that the number of nerve fibres located in the nipple and in the parenchyma of the gland containing TH and other studied peptides is sympathetic components of the autonomic nervous system (Eriksson et al., ; Franke‐Radowiecka et al., ).…”

“…The sympathetic nervous system plays the most important function in the process of milk ejection (Lukasova et al., ; Eriksson et al., ; Aceves et al., ; Morales et al., ,b; Wellnitz and Bruckmaier, ; Marina et al., ). To date, the sympathetic innervation of the mammary gland was characterized in women (Eriksson et al., ) and different animal species, such as rat (Eriksson et al., ; Morales et al., ), goat (Linzell, ,b; Lukas et al., ; Lukasova et al., ), sheep (Linzell, ,b; Ivanov et al., ), cat (Linzell, ), rabbit (Hebb and Linzell, ; Mena et al., ), cow (Linzell, ; Hebb and Linzell, ; Cowie, ; Maśliński et al., ; Michel, ), dog (Pinho and Gulbenkian, ) and pig (Franke‐Radowiecka et al., ). It was found that the sympathetic nervous system is involved in the regulation of local blood flow and effect on inhibition of the milk ejection (Mena et al., ; Eriksson et al., ; Morales et al., ,b; Wellnitz and Bruckmaier, ; Marina et al., ).…”

“…To date, the sympathetic innervation of the mammary gland was characterized in women (Eriksson et al., ) and different animal species, such as rat (Eriksson et al., ; Morales et al., ), goat (Linzell, ,b; Lukas et al., ; Lukasova et al., ), sheep (Linzell, ,b; Ivanov et al., ), cat (Linzell, ), rabbit (Hebb and Linzell, ; Mena et al., ), cow (Linzell, ; Hebb and Linzell, ; Cowie, ; Maśliński et al., ; Michel, ), dog (Pinho and Gulbenkian, ) and pig (Franke‐Radowiecka et al., ). It was found that the sympathetic nervous system is involved in the regulation of local blood flow and effect on inhibition of the milk ejection (Mena et al., ; Eriksson et al., ; Morales et al., ,b; Wellnitz and Bruckmaier, ; Marina et al., ). Emerging evidence suggests that there are two mechanisms that are responsible for the inhibition of the secretion of milk, the central and peripheral mechanism (Morales et al., ,b; Wellnitz and Bruckmaier, ).…”

“…Catecholamines circulating in the blood cause the inhibition of the oxytocin releasing from the hypothalamus (Mena et al., ; Morales et al., ,b; Wellnitz and Bruckmaier, ). Catecholamines also bind to α ‐adrenergic receptors on myoepithelial cells which surround lactiferous ducts, or occur in the nipple, and cause that relaxation (Mena et al., ; Morales et al., ,b; Wellnitz and Bruckmaier, ).…”