Functional analysis of the feeding apparatus and digestive tract anatomy of the aardwolf Proteles cristatus

The aardwolf is unique amongst the myrmecophagous mammals in that it feeds almost exclusively on one genus of termite, Trinervitermes , yet it possesses none of the obvious external physical features (elongated snout, powerful limbs and claws) characteristic of this feeding style. Externally it looks simply like a diminutive hyaena. Behaviourally the aardwolf differs from the other typical 'anteaters', in that it does not dig for its prey, but licks them off the soil surface. Nevertheless, the aardwolf does have a number of anatomical features which are clearly adaptations to this diet. The most obvious of these are a broad spatulate tongue covered with large, hardened papillae, a broad palate, large mandibular salivary glands, and a muscular pyloric region in the stomach. A relatively short small intestine facilitates the rapid processing of large volumes of termites, while a distensible large intestine allows for the accumulation of faecal material. Some of these features associated with feeding and digestion are compared with those of the domestic dog Canis familiaris , the bat-eared fox Otocyon megalotis and the black-backed jackal Canis mesomelas .     

Periodontal disease in southern African bushpigs (Potamochoerus porcus) and warthogs (Phacochoerus aethiopicus)

Periodontal lesions were found in 14 of 100 bushpig (Potamochoerus porcus) skulls and nine of 103 warthog (Phacochoerus aethiopicus) skulls from southern Africa. The prevalence of periodontal disease showed a significant increase with age in the bushpig but not in the warthog skulls. All the lesions affected the cheek teeth, particularly the molars. The lower prevalence of lesions in older warthogs may be associated with their specialised molars and abrasive diet.     

Halothane alters contractility and Ca2+ transport in ventricular myocytes from streptozotocin-induced diabetic rats

General anaesthetics have previously been shown to have profound effects on myocardial function. Moreover, many patients suffering from diabetes mellitus are anaesthetised during surgery. This study investigated compromised functioning of cardiac myocytes from streptozotocin (STZ)-induced diabetic rats and the additive effects of halothane on these dysfunctions. Ventricular myocytes were isolated from 8 to 12 weeks STZ-treated rats. Contraction and intracellular free calcium concentration ([Ca²⁺] _i ) were measured in electrically field-stimulated (1 Hz) fura-2-AM-loaded cells using a video-edge detection system and a fluorescence photometry system, respectively. L-type Ca²⁺ current was measured in whole cell, voltage-clamp mode. Halothane significantly (p < 0.01) depressed the amplitude and the time course of the Ca²⁺ transients in a similar manner in myocytes from control and STZ-treated rats. However, the effect of halothane on the amplitude of shortening and L-type Ca²⁺ current was more pronounced in myocytes from STZ-treated animals compared to age-matched controls. Myofilament sensitivity to Ca²⁺ was significantly (p < 0.01) increased in myocytes from STZ-treated rats compared to control. However, in the presence of halothane the myofilament sensitivity to Ca²⁺ was significantly (p < 0.05) reduced to a greater extent in myocytes from STZ-treated rats compared to controls. In conclusion, these results show that contractility, Ca²⁺ transport and myofilament sensitivity were all altered in myocytes from STZ-treated rats and these processes were further altered in the presence of halothane suggesting that hearts from STZ-induced diabetic rats are sensitive to halothane. (Mol Cell Biochem 261: 251–261, 2004)