CILIA 



80 



CILIA 



on the frog's palate by Lucas, A. M. 

 (Arch. Otolaryng., 1933, 18, 516-524). 

 Hill, L. (Lancet, 1928, 2, 802-805) had 

 previously shown that cuts across the 

 trachea arranged in alternating fashion 

 completely stopped the flow of mucus 

 and also showed a high sensitivity to 

 ultra violet light. A combination of 

 both direct and indirect techniques 

 gives the most accurate results. The 

 double nature of the mucous layer and 

 the three ways in which ciliary move- 

 ment and mucous flow could act to- 

 gether or independently were suggested 

 by Lucas, A. M., and Douglas, L. C. 

 (Arch. Otolaryng., 1934, 20, 518-541). 



Most ciliary activity can be defined 

 in terms of work. Bowditch, H. P. 

 (Boston Med. and Surg. J., 1876, 15, 

 159-164), one of the first to study this 

 problem, permitted a sheet of ciliated 

 epithelium from the frog to climb up an 

 inclined plane set at various angles and 

 carrying various loads. He cooncluded 

 that cilia are capable of doing only 

 about one-thirty-fifth the work that the 

 heart does in pumping blood. Parker, 

 G. H. (J. Exp. Zool., 1914, 16, 443-446) 

 placed a tube in the osculum of the 

 sponge and ascertained that the pres- 

 sure developed in the system by the 

 collar cells was only a few millimeters 

 but that the volume turn-over was 

 large. A similar technique was applied 

 by Hecht, S. (J. Exp. Zool., 1916, 20, 

 429-434) to the large Bermuda ascidian. 

 A 100 gm. animal could circulate about 

 173 liters of sea water in a day. Hecht 

 gives his technique for getting the glass 

 tube into the excurrent siphon. Galt- 

 soff, P. S. (Bull. U. S. Bur. Fish. 1928 

 (1930) 44, 1-39) has gone farther than 

 anyone thus far in designing apparatus 

 to measure rate of flow of water due to 

 ciliary action. He used the oyster and 

 collected data on feeding and effects 

 of temperature and seasonal and diurnal 

 cycles. Hilding, A. C. (Trans. Am. 

 Acad. Opth. and Otolaryng., 1944, 367- 

 378) found that the trachea of the hen 

 was particularly well suited to measure 

 the positive and negative pressures de- 

 veloped at the two ends of the tube. 

 He collected mucus from other hens 

 and used it to form a plug at the lower 

 end of the trachea being tested. A 

 negative pressure of 34 mm. and a posi- 

 tive pressure of 32 mm. of water was 

 developed at the two ends of the tube. 

 The techniques used are simple but 

 effective. The procedures devised by 

 White, H. L. (Am. J. Physiol., 1929, 

 90, 689-704) to measure the pressure 

 developed by the nephostomal cilia in 

 the Necturus kidney is a good example 

 of how the microscopic methods can be 



applied. In general, in vivo studies of 

 ciliary movement have been rather few 

 but a nice technique was used by Ernst, 

 A. M. (Arch. Internat. Pharmacodyn. 

 et de Th^rap., 1938, 58, 207-212) in 

 which periodic roentograms were made 

 of the cat's thorax to show the rate of 

 elimination of "Neobar" powder 

 (Merck) which had previously been 

 blown into the trachea and bronchial 

 spaces. Normally the trachea was 

 cleared in an hour and from this base- 

 line the effect of various anesthetics 

 could be determined. X-ray radiation 

 in itself has very little effect on ciliary 

 activity as shown by Goldhaber, A., 

 and Black, A. (Proc. Soc. Exp. Biol, 

 and Med., 1941, 48, 150-151) who ob- 

 served that the oral epithelium of the 

 toad transplanted as a tissue culture 

 required 1,000,000 to 1,400,000 r to stop 

 ciliary activity. The essential details 

 of their x-ray set-up are given. 



Numerous papers mention the pres- 

 ence of cilia lining various parts of the 

 central canal of the nervous system and 

 suggestions have been offered concern- 

 ing the function they perform but only 

 one author (Chu, H. Y., Am. J. Physiol., 

 1942, 136, 223-228) to our knowledge 

 has selected a suitable material (trans- 

 lucent stages of amphibian larva) and 

 thus been able to study this activity 

 in situ. He followed the movements 

 of naturally occurring pigment granules 

 within the ventricles and also injected 

 red cells. 



Satisfactory methods for examination 

 of ciliary movement in tubular organs 

 such as the lungs are not always easy. 

 SoUmann, T., and Gilbert, A. J. (J. 

 Pharmacol, and Exp. Therap., 1937, 61, 

 272-285) filled the excised organ with 

 10 per cent gelatin in Ringers and then 

 chilled it in iced Ringers. Free-hand 

 sections were pinned on rings of cork 

 and studied in shallow dishes contain- 

 ing Ringer's warmed to 37 °C. Cilia 

 were vigorously active up to about 8 

 hrs. 



A method for testing the phagocytic 

 properties of ciliated epithelium was 

 employed by Ropes, M. W. (Contrib. 

 to Embryol. #128, Carnegie Inst., 

 Wash., 1930, 22, 77-90). He used the 

 tracheal mucosa of the rabbit. In- 

 haled carbon particles were taken up by 

 the cytoplasm and could be recognized 

 in the living ciliated cells. 



The older editions of Lee's Vade 

 Mecum suggest boric acid methods for 

 maceration of ciliated epithelia. This 

 technique has been omitted from some 

 of the more recent editions but is men- 

 tioned again in the last edition (11th). 

 The method was revived by Goodrich, 



