The structural organization and the steroidogenic responsiveness in vitro of adrenal gland tissue from the neonatal mallard duck (Anas platyrhynchos)

The Effects of Capture, Restraint, and Transport on Hematologic, Plasma Biochemical, and Blood Gas Values in Dalmatian Pelicans ( Pelecanus crispus)

To determine the effect of capture and restraint on hematologic, plasma biochemical, and venous blood gas values in Dalmatian pelicans ( Pelecanus crispus), blood samples were collected and temperature and heart rate were recorded in 13 pelicans (5 males and 8 females) immediately after capture from a large field exhibit. Repeat sampling was performed after transport, a mean of 74 minutes after initial evaluation. When compared with values at initial sampling to the time of capture, significant increases were documented in the heterophil : lymphocyte ratio (H : L), carbon dioxide (CO₂), bicarbonate (HCO₃), total carbon dioxide (Tco₂), base excess (BE), and partial pressure of carbon dioxide (Pco₂) values after 74 minutes. Significant decreases were documented in total protein, lactate, and phosphorus concentrations, percentage of oxygen saturation (So₂), partial pressure of oxygen (Po₂), total white blood cell count (WBC), absolute lymphocytes, absolute eosinophils, and absolute monocytes after 74 minutes. Those changes suggest capture and restraint can alter hematologic, plasma biochemical, and acid-base status in Dalmatian pelicans, which may influence clinical decision making and case management.

A comparison of the responses of dispersed steroidogenic cells derived from embryonic adrenal tissue from the domestic chicken (Gallus domesticus), the domestic Pekin duck and the wild mallard duck (Anas platyrhynchos), and the domestic muscovy duck (Cairina moschata)

The steroidogenic responsiveness of adrenal cell suspensions prepared from domestic chicken adrenal tissue at the end of embryogenesis was compared to the responses of similar preparations derived from the wild and domesticated mallard duck (Anas platyrhynchos), and the domesticated muscovy duck (Cairina moschata). In all cases, the masses of corticosterone (B), aldosterone (Aldo), and deoxycorticosterone (DOC) released from cells incubated in medium containing 1-24 ACTH exceeded the estimated hormone content of the freshly dispersed cells; the induced rates of corticosteroid release were, therefore, presumed to reflect de novo hormone synthesis. When chicken cells were incubated in medium containing 1-24 ACTH, there were progressive, dose-dependent increases in B and DOC synthesis over a range of concentrations spanning two orders of magnitude; only small, non-dose-related, albeit significant, increases in Aldo release were observed. The 1-24 ACTH-induced increases in B and Aldo synthesis by the mallard and Pekin duck cells exposed to the same range of concentrations were up to 40 and 60 times greater than the corresponding responses of the chicken cells. The rates of 1-24 ACTH-induced B and DOC release from muscovy duck cells were similar to those from the Pekin duck cells; compared with the mallard duck cells, however, the muscovy duck cells were less sensitive and the maximum inducible rate of B release was significantly lower. The pattern of 1-24 ACTH-induced Aldo release from the muscovy duck cells was indistinguishable from that of the mallard duck cells, although the maximum inducible increase occurred at a lower concentration. Angiotensin II (AII) induced very small, but significant increased in B, Aldo, and DOC release from the chicken cells but in a nondose-related fashion. In contrast, mallard, Pekin, and muscovy duck cells all responded in a dose-dependent manner when incubated in medium containing AII. In each instance the maximum rate of Aldo synthesis induced by AII was about one-tenth of the corresponding rate induced by 1-24 ACTH. The maximum rates of B synthesis induced by AII, however, were extremely low compared with the rates induced by 1-24 ACTH. Thus, when maximally stimulated with AII the B:Aldo output ratio ranged from 1.0 to 1.9, whereas the corresponding ratio was between 9.0 and 17.0 when the cells were maximally stimulated with 1-24 ACTH.

Functional and morphological changes associated with the ageing of primary cultures of embryonic adrenal gland cells derived from the Pekin duck

The morphological and functional changes associated with ageing were studied in adrenal steroidogenic cells derived from duck embryos. Cells grown for not more than three days had structural characteristics similar to their counterparts in vivo; they contained numerous lipid droplets and mitochondria, an abundant smooth endoplasmic reticulum, an even network of microtubules, and microfilaments that formed extensive and elaborate systems of parallel stress fibers. After the 3rd day of growth in culture, many of the cells started to decrease in size and become elongated; the older cells showed less well-defined actin filaments and contained elongated mitochondria, fewer lipid droplets, less smooth endoplasmic reticulum, and swollen cisternae of rough endoplasmic reticulum. The proliferative capacity of the cells was the same when they were cultured in either the presence or the absence of 1-24 ACTH. After the first day of growth in culture, the steroidogenic capacity of the cells declined and the addition of 1-24 ACTH to the growth medium did not prevent changes in their structure and function. The decline in steroidogenic capacity occurred both in terms of the amount of hormone released into the culture medium and in the ability of the cells to respond when incubated in buffer containing 1-24 ACTH. Since the basal unstimulated rates of corticosteroid production also declined as the cells aged, it is probable that the steroidogenic deficiency occurs at a site distal to the corticotropin receptor; this is also consistent with the ultrastructural observations that suggest a relationship between the morphological changes and the decline in steroidogenic capacity as the cells age.